Release v2.1.0: backend test seam, captive-portal detection, JSON status, robustness

Features:
- Introduce a Backend trait + System impl so flow/status/watch can be unit
  tested against a fake; add 11 connect-state-machine tests.
- Captive-portal detection: status::connectivity returns Online/Portal/Offline;
  surfaced in status, JSON, connect notes, and a dedicated watch state.
- `status --json` for bars/scripts; `profile add`/`profile remove`; detect now
  scores by number of in-range markers.

Robustness:
- Pin LC_ALL=C/LANG=C on child processes for locale-independent parsing.
- Atomic config/state writes (temp + rename); 0600 config never world-readable.
- Transient PSK file written to $XDG_RUNTIME_DIR when available.

Fixes (from prior audit):
- Feed Wi-Fi PSK to nmcli via stdin/passwd-file, never argv.
- mask() no longer panics on multi-byte passwords.
- Connectivity check requires HTTP 204 (no captive-portal false positives).
- nmcli NAME,TYPE parsing handles escaped colons.
- Strip CIDR suffix from displayed IP; PKGBUILD/Cargo version aligned (2.1.0).

.github/workflows/release.yml

@@ -17,9 +17,6 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - name: install build deps
-        run: sudo apt-get install -y libnm-dev libdbus-1-dev pkg-config 2>/dev/null || true
-
       - name: build
         run: cargo build --release --locked
 

Cargo.lock

@@ -54,7 +54,7 @@ dependencies = [
 
 [[package]]
 name = "breadcrumbs"
-version = "2.0.1"
+version = "2.1.0"
 dependencies = [
  "clap",
  "serde",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "breadcrumbs"
-version = "2.0.1"
+version = "2.1.0"
 edition = "2021"
 description = "Profile-aware Wi-Fi state machine with Tailscale handling and self-healing watch daemon"
 license = "MIT"

README.md

@@ -9,8 +9,10 @@ breadcrumbs sits on top of NetworkManager (`nmcli`) and manages your Wi-Fi based
 - **Profile-based connection management** — define ordered network priority lists per location
 - **Bootstrap + Tailscale gating** — connect to an interim network first, bring up Tailscale, then move to the target network
 - **Self-healing watch daemon** — monitors for drops, auto-recovers, reacts within seconds via `nmcli monitor`
-- **Auto-detection** — scans visible SSIDs and guesses your location from config-defined markers
+- **Auto-detection** — scans visible SSIDs and guesses your location from config-defined markers (picks the profile with the most markers in range)
-- **Secure credential handling** — passwords fed to `nmcli` via stdin (never in argv/`ps`), config stored at 0600
+- **Captive-portal detection** — distinguishes a real connection from a sign-in page and surfaces the portal URL instead of falsely reporting "online"
+- **Secure credential handling** — passwords fed to `nmcli` out-of-band (via stdin with `--ask`, or a 0600 `passwd-file`), never in argv/`ps`; config stored at 0600
+- **Machine-readable status** — `breadcrumbs status --json` for bars/scripts
 - **Desktop notifications** via `notify-send` (optional)
 - **systemd user service** generation via `breadcrumbs install-service`
 
@@ -25,7 +27,7 @@ breadcrumbs sits on top of NetworkManager (`nmcli`) and manages your Wi-Fi based
 ## Installation
 
 ```bash
-git clone https://github.com/breadway/breadcrumbs
+git clone https://github.com/Breadway/breadcrumbs
 cd breadcrumbs
 cargo build --release
 # Copy to somewhere on your PATH:
@@ -95,12 +97,14 @@ breadcrumbs [--profile <name>] <command>
 
 | Command | Description |
 |---------|-------------|
-| `status` | Show current Wi-Fi / Tailscale health (default) |
+| `status [--json]` | Show current Wi-Fi / Tailscale health (default); `--json` for scripts |
 | `init` | Run the full connect sequence for the active profile |
 | `watch [--no-initial]` | Self-healing daemon: monitors and auto-recovers drops |
 | `profile get` | Print the active profile |
 | `profile set <name>` | Switch profile (and apply it, unless `--no-apply`) |
 | `profile list` | List all profiles |
+| `profile add <name> [--detect <ssid>]…` | Create a new (empty) profile, optionally with detection markers |
+| `profile remove <name>` | Delete a profile (core `home`/`work`/`away` are protected) |
 | `detect [--apply]` | Guess profile from visible networks; optionally apply it |
 | `add <ssid> [password]` | Add or update a saved network |
 | `forget <ssid>` | Remove a network from config and NetworkManager |

breadcrumbs.example.toml

@@ -11,6 +11,8 @@ nmcli_wait = 8
 exit_node = "my-exit-node"     # Tailscale hostname of your preferred exit node
 default_profile = "away"
 watch_interval = 12
+# Must be a "generate_204"-style endpoint: only an empty HTTP 204 counts as
+# online, so a captive portal (200 login page / 30x redirect) is detected.
 connectivity_url = "http://connectivitycheck.gstatic.com/generate_204"
 ping_host = "1.1.1.1"
 

packaging/arch/PKGBUILD

@@ -1,7 +1,7 @@
 # Maintainer: Breadway <rileyhorsham@gmail.com>
 
 pkgname=breadcrumbs
-pkgver=0.1.0
+pkgver=2.1.0
 pkgrel=1
 pkgdesc="Profile-aware Wi-Fi state machine with Tailscale integration"
 arch=('x86_64')

src/backend.rs

@@ -0,0 +1,80 @@
+//! The seam between breadcrumbs' decision logic and the outside world.
+//!
+//! Every interaction with NetworkManager, Tailscale, connectivity probes,
+//! notifications and logging goes through the [`Backend`] trait. Production code
+//! uses [`System`], which delegates to the `nm`/`tailscale`/`status`/`notify`
+//! modules that shell out. Tests inject a fake so the connect state machine
+//! (`flow`) and watch classifier can be exercised without touching the host.
+
+use std::collections::HashSet;
+
+use crate::config::{Config, NetworkDef};
+use crate::nm;
+use crate::notify::{self, Urgency};
+use crate::status::{self, Connectivity};
+use crate::tailscale::{self, TsHealth};
+
+pub trait Backend {
+    fn wifi_interface(&self) -> Option<String>;
+    fn radio_on(&self);
+    fn rescan(&self, iface: &str, ssids: &[String]);
+    fn visible_ssids(&self, iface: &str) -> HashSet<String>;
+    fn active_ssid(&self, iface: &str) -> Option<String>;
+    fn ipv4(&self, iface: &str) -> Option<String>;
+    fn device_connected(&self, iface: &str) -> bool;
+    fn connect(&self, iface: &str, net: &NetworkDef, wait: u32, dns: &str) -> Result<(), String>;
+    fn tailscale_installed(&self) -> bool;
+    fn ensure_exit_node(&self, node: &str) -> TsHealth;
+    fn tailscale_check(&self, node: &str) -> TsHealth;
+    fn connectivity(&self, cfg: &Config) -> Connectivity;
+    fn notify(&self, summary: &str, body: &str, urgency: Urgency);
+    fn log(&self, line: &str);
+}
+
+/// The real backend: every method delegates to the system-facing modules.
+pub struct System;
+
+impl Backend for System {
+    fn wifi_interface(&self) -> Option<String> {
+        nm::wifi_interface()
+    }
+    fn radio_on(&self) {
+        nm::radio_on()
+    }
+    fn rescan(&self, iface: &str, ssids: &[String]) {
+        nm::rescan(iface, ssids)
+    }
+    fn visible_ssids(&self, iface: &str) -> HashSet<String> {
+        nm::visible_ssids(iface)
+    }
+    fn active_ssid(&self, iface: &str) -> Option<String> {
+        nm::active_ssid(iface)
+    }
+    fn ipv4(&self, iface: &str) -> Option<String> {
+        status::ipv4(iface)
+    }
+    fn device_connected(&self, iface: &str) -> bool {
+        nm::device_connected(iface)
+    }
+    fn connect(&self, iface: &str, net: &NetworkDef, wait: u32, dns: &str) -> Result<(), String> {
+        nm::connect_verbose(iface, net, wait, dns)
+    }
+    fn tailscale_installed(&self) -> bool {
+        tailscale::installed()
+    }
+    fn ensure_exit_node(&self, node: &str) -> TsHealth {
+        tailscale::ensure_exit_node(node)
+    }
+    fn tailscale_check(&self, node: &str) -> TsHealth {
+        tailscale::check(node)
+    }
+    fn connectivity(&self, cfg: &Config) -> Connectivity {
+        status::connectivity(cfg)
+    }
+    fn notify(&self, summary: &str, body: &str, urgency: Urgency) {
+        notify::notify(summary, body, urgency)
+    }
+    fn log(&self, line: &str) {
+        notify::log(line)
+    }
+}

src/config.rs

@@ -158,13 +158,10 @@ impl Config {
         fs::create_dir_all(&dir).map_err(|e| format!("creating {}: {e}", dir.display()))?;
         let text = toml::to_string_pretty(self).map_err(|e| format!("serializing config: {e}"))?;
         let path = config_path();
-        fs::write(&path, text).map_err(|e| format!("writing {}: {e}", path.display()))?;
+        // Plaintext Wi-Fi passwords live here: write atomically and owner-only,
-        // Plaintext Wi-Fi passwords live here — keep it owner-only.
+        // so there's no torn read and no world-readable window.
-        #[cfg(unix)]
+        crate::util::write_atomic(&path, &text, 0o600)
-        {
+            .map_err(|e| format!("writing {}: {e}", path.display()))?;
-            use std::os::unix::fs::PermissionsExt;
-            let _ = fs::set_permissions(&path, fs::Permissions::from_mode(0o600));
-        }
         Ok(())
     }
 }
@@ -274,4 +271,124 @@ mod tests {
         assert!(cfg.profile("work").is_some());
         assert!(cfg.profile("away").is_some());
     }
+
+    #[test]
+    fn ensure_core_profiles_does_not_overwrite_existing() {
+        let mut cfg = Config {
+            settings: Settings::default(),
+            networks: vec![],
+            profiles: BTreeMap::new(),
+        };
+        cfg.profiles.insert(
+            "home".to_string(),
+            Profile {
+                tailscale: true,
+                exit_node: Some("mynode".into()),
+                ..Default::default()
+            },
+        );
+        ensure_core_profiles(&mut cfg);
+        let home = cfg.profile("home").unwrap();
+        assert!(home.tailscale, "existing field should be preserved");
+        assert_eq!(home.exit_node.as_deref(), Some("mynode"));
+    }
+
+    #[test]
+    fn network_lookup_found_and_not_found() {
+        let mut cfg = build_initial_config();
+        cfg.networks.push(NetworkDef {
+            ssid: "TestNet".into(),
+            password: "secret".into(),
+            hidden: false,
+        });
+        let found = cfg.network("TestNet");
+        assert!(found.is_some());
+        assert_eq!(found.unwrap().password, "secret");
+        assert!(cfg.network("NoSuchSSID").is_none());
+    }
+
+    #[test]
+    fn profile_lookup_found_and_not_found() {
+        let cfg = build_initial_config();
+        assert!(cfg.profile("home").is_some());
+        assert!(cfg.profile("nonexistent").is_none());
+    }
+
+    #[test]
+    fn settings_default_values() {
+        let s = Settings::default();
+        assert_eq!(s.dns, "1.1.1.1");
+        assert_eq!(s.nmcli_wait, 8);
+        assert!(s.exit_node.is_empty());
+        assert_eq!(s.default_profile, "away");
+        assert_eq!(s.watch_interval, 12);
+        assert!(!s.connectivity_url.is_empty());
+        assert!(!s.ping_host.is_empty());
+    }
+
+    #[test]
+    fn config_toml_roundtrip_with_hidden_network() {
+        let mut cfg = build_initial_config();
+        cfg.networks.push(NetworkDef {
+            ssid: "HiddenNet".into(),
+            password: "pw".into(),
+            hidden: true,
+        });
+        cfg.networks.push(NetworkDef {
+            ssid: "VisibleNet".into(),
+            password: "pw2".into(),
+            hidden: false,
+        });
+        let text = toml::to_string_pretty(&cfg).unwrap();
+        let back: Config = toml::from_str(&text).unwrap();
+        assert_eq!(back.networks.len(), 2);
+        let hidden = back.network("HiddenNet").unwrap();
+        assert!(hidden.hidden);
+        let visible = back.network("VisibleNet").unwrap();
+        assert!(!visible.hidden);
+    }
+
+    #[test]
+    fn config_toml_roundtrip_with_full_profile_fields() {
+        let mut cfg = build_initial_config();
+        let work = cfg.profiles.get_mut("work").unwrap();
+        work.tailscale = true;
+        work.exit_node = Some("myexit".into());
+        work.bootstrap = Some("BootstrapSSID".into());
+        work.detect_ssids = vec!["WorkWifi".into(), "CorpGuest".into()];
+        work.networks = vec!["WorkWifi".into()];
+        let text = toml::to_string_pretty(&cfg).unwrap();
+        let back: Config = toml::from_str(&text).unwrap();
+        let w = back.profile("work").unwrap();
+        assert!(w.tailscale);
+        assert_eq!(w.exit_node.as_deref(), Some("myexit"));
+        assert_eq!(w.bootstrap.as_deref(), Some("BootstrapSSID"));
+        assert_eq!(w.detect_ssids, vec!["WorkWifi", "CorpGuest"]);
+        assert_eq!(w.networks, vec!["WorkWifi"]);
+    }
+
+    #[test]
+    fn config_deserialization_applies_settings_defaults_for_missing_fields() {
+        let toml_str = r#"
+[settings]
+dns = "8.8.8.8"
+"#;
+        let cfg: Config = toml::from_str(toml_str).unwrap();
+        assert_eq!(cfg.settings.dns, "8.8.8.8");
+        // Fields not specified should get their defaults.
+        assert_eq!(cfg.settings.nmcli_wait, 8);
+        assert_eq!(cfg.settings.default_profile, "away");
+        assert_eq!(cfg.settings.watch_interval, 12);
+    }
+
+    #[test]
+    fn network_def_hidden_defaults_to_false() {
+        let toml_str = r#"
+[[networks]]
+ssid = "MyNet"
+password = "pass"
+"#;
+        let cfg: Config = toml::from_str(toml_str).unwrap();
+        assert!(!cfg.networks[0].hidden);
+    }
 }

src/flow.rs

@@ -1,8 +1,8 @@
+use crate::backend::Backend;
 use crate::config::{Config, NetworkDef};
-use crate::nm;
+use crate::notify::Urgency;
-use crate::notify::{log, notify, Urgency};
+use crate::status::Connectivity;
-use crate::status::internet_ok;
+use crate::tailscale::TsHealth;
-use crate::tailscale::{self, TsHealth};
 
 #[derive(Debug)]
 pub enum Outcome {
@@ -48,20 +48,35 @@ fn resolve_candidates<'a>(cfg: &'a Config, p: &crate::config::Profile) -> Vec<&'
 
 /// Try to connect + confirm it actually carries traffic.
 /// Returns Ok(()) on success, Err(reason) on failure.
-fn connect_and_verify(iface: &str, def: &NetworkDef, cfg: &Config) -> Result<(), String> {
+fn connect_and_verify(
-    nm::connect_verbose(iface, def, cfg.settings.nmcli_wait, &cfg.settings.dns)?;
+    be: &dyn Backend,
-    if !nm::device_connected(iface) {
+    iface: &str,
+    def: &NetworkDef,
+    cfg: &Config,
+) -> Result<(), String> {
+    be.connect(iface, def, cfg.settings.nmcli_wait, &cfg.settings.dns)?;
+    if !be.device_connected(iface) {
         return Err("device not connected after nmcli success".into());
     }
     Ok(())
 }
 
+/// Describe post-association connectivity as an optional caveat note.
+fn connectivity_note(be: &dyn Backend, cfg: &Config) -> Option<String> {
+    match be.connectivity(cfg) {
+        Connectivity::Online => None,
+        Connectivity::Portal(Some(url)) => Some(format!("captive portal — sign in at {url}")),
+        Connectivity::Portal(None) => Some("captive portal — sign in required".into()),
+        Connectivity::Offline => Some("associated but no internet yet".into()),
+    }
+}
+
 /// Run the connection state machine for `profile_name`.
-pub fn run(cfg: &Config, profile_name: &str) -> Outcome {
+pub fn run(be: &dyn Backend, cfg: &Config, profile_name: &str) -> Outcome {
     let profile = match cfg.profile(profile_name) {
         Some(p) => p.clone(),
         None => {
-            notify(
+            be.notify(
                 "breadcrumbs: unknown profile",
                 &format!("'{profile_name}' is not defined in breadcrumbs.toml"),
                 Urgency::Critical,
@@ -70,10 +85,10 @@ pub fn run(cfg: &Config, profile_name: &str) -> Outcome {
         }
     };
 
-    let iface = match nm::wifi_interface() {
+    let iface = match be.wifi_interface() {
         Some(i) => i,
         None => {
-            notify(
+            be.notify(
                 "breadcrumbs: no Wi-Fi adapter",
                 "Hardware issue — Wi-Fi device not found. Manual check needed.",
                 Urgency::Critical,
@@ -81,7 +96,7 @@ pub fn run(cfg: &Config, profile_name: &str) -> Outcome {
             return Outcome::NoInterface;
         }
     };
-    nm::radio_on();
+    be.radio_on();
 
     let exit_node = profile
         .exit_node
@@ -89,7 +104,7 @@ pub fn run(cfg: &Config, profile_name: &str) -> Outcome {
         .unwrap_or_else(|| cfg.settings.exit_node.clone());
     let candidates = resolve_candidates(cfg, &profile);
 
-    log(&format!(
+    be.log(&format!(
         "flow start: profile={profile_name} iface={iface} tailscale={} candidates=[{}]",
         profile.tailscale,
         candidates
@@ -104,8 +119,8 @@ pub fn run(cfg: &Config, profile_name: &str) -> Outcome {
     if let Some(bs) = &profile.bootstrap {
         scan_targets.push(bs.clone());
     }
-    nm::rescan(&iface, &scan_targets);
+    be.rescan(&iface, &scan_targets);
-    let visible = nm::visible_ssids(&iface);
+    let visible = be.visible_ssids(&iface);
 
     // ---- Tailscale-gated profiles (e.g. school) -------------------------
     let mut on_bootstrap = false;
@@ -114,29 +129,29 @@ pub fn run(cfg: &Config, profile_name: &str) -> Outcome {
             match cfg.network(&bs_ssid) {
                 Some(bdef) => {
                     if visible.contains(&bdef.ssid) || bdef.hidden {
-                        match connect_and_verify(&iface, bdef, cfg) {
+                        match connect_and_verify(be, &iface, bdef, cfg) {
                             Ok(()) => {
                                 on_bootstrap = true;
-                                log(&format!("bootstrap connected: {}", bdef.ssid));
+                                be.log(&format!("bootstrap connected: {}", bdef.ssid));
                             }
                             Err(e) => {
-                                log(&format!("bootstrap connect failed: {} — {e}", bdef.ssid))
+                                be.log(&format!("bootstrap connect failed: {} — {e}", bdef.ssid))
                             }
                         }
                     } else {
-                        log(&format!("bootstrap not in range: {}", bdef.ssid));
+                        be.log(&format!("bootstrap not in range: {}", bdef.ssid));
                     }
                 }
-                None => log(&format!(
+                None => be.log(&format!(
                     "bootstrap SSID '{bs_ssid}' has no credentials in config"
                 )),
             }
         }
 
-        let ts = tailscale::ensure_exit_node(&exit_node);
+        let ts = be.ensure_exit_node(&exit_node);
         if !ts.is_ok() {
-            let ssid = nm::active_ssid(&iface).or_else(|| profile.bootstrap.clone());
+            let ssid = be.active_ssid(&iface).or_else(|| profile.bootstrap.clone());
-            notify(
+            be.notify(
                 "Tailscale Error",
                 &format!(
                     "{} — staying on {}",
@@ -147,12 +162,12 @@ pub fn run(cfg: &Config, profile_name: &str) -> Outcome {
             );
             return Outcome::TailscaleError { ssid, health: ts };
         }
-        log(&format!("tailscale healthy via exit node {exit_node}"));
+        be.log(&format!("tailscale healthy via exit node {exit_node}"));
         // Refresh visibility before moving to the target network.
-        nm::rescan(&iface, &scan_targets);
+        be.rescan(&iface, &scan_targets);
     }
 
-    let visible = nm::visible_ssids(&iface);
+    let visible = be.visible_ssids(&iface);
 
     // ---- Connect to the priority list ----------------------------------
     // Pass 1: visible networks in priority order.
@@ -160,20 +175,16 @@ pub fn run(cfg: &Config, profile_name: &str) -> Outcome {
     for def in &candidates {
         if visible.contains(&def.ssid) {
             any_attempted = true;
-            match connect_and_verify(&iface, def, cfg) {
+            match connect_and_verify(be, &iface, def, cfg) {
                 Ok(()) => {
-                    let note = if internet_ok(cfg) {
+                    let note = connectivity_note(be, cfg);
-                        None
+                    finish_connected(be, &def.ssid, profile_name, &note);
-                    } else {
-                        Some("associated but no internet yet".to_string())
-                    };
-                    finish_connected(&def.ssid, profile_name, &note);
                     return Outcome::Connected {
                         ssid: def.ssid.clone(),
                         note,
                     };
                 }
-                Err(e) => log(&format!("connect failed (visible): {} — {e}", def.ssid)),
+                Err(e) => be.log(&format!("connect failed (visible): {} — {e}", def.ssid)),
             }
         }
     }
@@ -181,20 +192,16 @@ pub fn run(cfg: &Config, profile_name: &str) -> Outcome {
     for def in &candidates {
         if def.hidden && !visible.contains(&def.ssid) {
             any_attempted = true;
-            match connect_and_verify(&iface, def, cfg) {
+            match connect_and_verify(be, &iface, def, cfg) {
                 Ok(()) => {
-                    let note = if internet_ok(cfg) {
+                    let note = connectivity_note(be, cfg);
-                        None
+                    finish_connected(be, &def.ssid, profile_name, &note);
-                    } else {
-                        Some("associated but no internet yet".to_string())
-                    };
-                    finish_connected(&def.ssid, profile_name, &note);
                     return Outcome::Connected {
                         ssid: def.ssid.clone(),
                         note,
                     };
                 }
-                Err(e) => log(&format!("connect failed (hidden): {} — {e}", def.ssid)),
+                Err(e) => be.log(&format!("connect failed (hidden): {} — {e}", def.ssid)),
             }
         }
     }
@@ -207,12 +214,12 @@ pub fn run(cfg: &Config, profile_name: &str) -> Outcome {
             .bootstrap
             .clone()
             .unwrap_or_else(|| "bootstrap".into());
-        if !nm::device_connected(&iface) {
+        if !be.device_connected(&iface) {
             if let Some(bdef) = profile.bootstrap.as_deref().and_then(|s| cfg.network(s)) {
-                match connect_and_verify(&iface, bdef, cfg) {
+                match connect_and_verify(be, &iface, bdef, cfg) {
-                    Ok(()) => log(&format!("bootstrap reconnected: {}", bdef.ssid)),
+                    Ok(()) => be.log(&format!("bootstrap reconnected: {}", bdef.ssid)),
                     Err(e) => {
-                        log(&format!("bootstrap reconnect failed: {} — {e}", bdef.ssid));
+                        be.log(&format!("bootstrap reconnect failed: {} — {e}", bdef.ssid));
                         on_bootstrap = false;
                     }
                 }
@@ -224,8 +231,8 @@ pub fn run(cfg: &Config, profile_name: &str) -> Outcome {
             } else {
                 format!("target network not in range — staying on {bs_ssid} (Tailscale OK)")
             };
-            notify("breadcrumbs: using bootstrap", &reason, Urgency::Normal);
+            be.notify("breadcrumbs: using bootstrap", &reason, Urgency::Normal);
-            log(&format!("flow end: on bootstrap {bs_ssid}; {reason}"));
+            be.log(&format!("flow end: on bootstrap {bs_ssid}; {reason}"));
             return Outcome::Connected {
                 ssid: bs_ssid,
                 note: Some(reason),
@@ -238,34 +245,34 @@ pub fn run(cfg: &Config, profile_name: &str) -> Outcome {
         .map(|c| c.ssid.as_str())
         .collect::<Vec<_>>()
         .join(", ");
-    notify(
+    be.notify(
         "breadcrumbs: no known networks",
         &format!("profile '{profile_name}': none of [{names}] are in range"),
         Urgency::Critical,
     );
-    log(&format!(
+    be.log(&format!(
         "flow end: no networks connected (profile={profile_name})"
     ));
     Outcome::NoNetworks
 }
 
-fn finish_connected(ssid: &str, profile: &str, note: &Option<String>) {
+fn finish_connected(be: &dyn Backend, ssid: &str, profile: &str, note: &Option<String>) {
     match note {
         None => {
-            notify(
+            be.notify(
                 "breadcrumbs: connected",
                 &format!("{ssid} ({profile})"),
                 Urgency::Low,
             );
-            log(&format!("flow end: connected {ssid} (profile={profile})"));
+            be.log(&format!("flow end: connected {ssid} (profile={profile})"));
         }
         Some(n) => {
-            notify(
+            be.notify(
                 "breadcrumbs: connected (degraded)",
                 &format!("{ssid} ({profile}) — {n}"),
                 Urgency::Normal,
             );
-            log(&format!(
+            be.log(&format!(
                 "flow end: connected {ssid} (profile={profile}) note={n}"
             ));
         }
@@ -276,6 +283,7 @@ fn finish_connected(ssid: &str, profile: &str, note: &Option<String>) {
 mod tests {
     use super::*;
     use crate::config::{Profile, Settings};
+    use crate::tailscale::TsHealth;
     use std::collections::BTreeMap;
 
     fn net(ssid: &str) -> NetworkDef {
@@ -299,6 +307,341 @@ mod tests {
         }
     }
 
+    // --- a scriptable in-memory Backend for testing the state machine ---
+
+    use std::cell::RefCell;
+    use std::collections::HashSet;
+
+    struct Fake {
+        iface: Option<String>,
+        visible: HashSet<String>,
+        connectable: HashSet<String>,
+        connected: RefCell<Option<String>>,
+        ts: TsHealth,
+        conn: Connectivity,
+        notes: RefCell<Vec<String>>,
+    }
+
+    impl Fake {
+        fn new() -> Fake {
+            Fake {
+                iface: Some("wlan0".into()),
+                visible: HashSet::new(),
+                connectable: HashSet::new(),
+                connected: RefCell::new(None),
+                ts: TsHealth::Ok,
+                conn: Connectivity::Online,
+                notes: RefCell::new(Vec::new()),
+            }
+        }
+        fn set(ssids: &[&str]) -> HashSet<String> {
+            ssids.iter().map(|s| s.to_string()).collect()
+        }
+        fn visible(mut self, ssids: &[&str]) -> Self {
+            self.visible = Fake::set(ssids);
+            self
+        }
+        fn connectable(mut self, ssids: &[&str]) -> Self {
+            self.connectable = Fake::set(ssids);
+            self
+        }
+        fn ts(mut self, h: TsHealth) -> Self {
+            self.ts = h;
+            self
+        }
+        fn conn(mut self, c: Connectivity) -> Self {
+            self.conn = c;
+            self
+        }
+        fn no_iface(mut self) -> Self {
+            self.iface = None;
+            self
+        }
+        fn notified(&self, needle: &str) -> bool {
+            self.notes.borrow().iter().any(|n| n.contains(needle))
+        }
+    }
+
+    impl Backend for Fake {
+        fn wifi_interface(&self) -> Option<String> {
+            self.iface.clone()
+        }
+        fn radio_on(&self) {}
+        fn rescan(&self, _: &str, _: &[String]) {}
+        fn visible_ssids(&self, _: &str) -> HashSet<String> {
+            self.visible.clone()
+        }
+        fn active_ssid(&self, _: &str) -> Option<String> {
+            self.connected.borrow().clone()
+        }
+        fn ipv4(&self, _: &str) -> Option<String> {
+            self.connected.borrow().as_ref().map(|_| "10.0.0.2".into())
+        }
+        fn device_connected(&self, _: &str) -> bool {
+            self.connected.borrow().is_some()
+        }
+        fn connect(&self, _: &str, net: &NetworkDef, _: u32, _: &str) -> Result<(), String> {
+            if self.connectable.contains(&net.ssid) {
+                *self.connected.borrow_mut() = Some(net.ssid.clone());
+                Ok(())
+            } else {
+                // A failed association drops the current link, like nmcli.
+                *self.connected.borrow_mut() = None;
+                Err(format!("cannot connect to {}", net.ssid))
+            }
+        }
+        fn tailscale_installed(&self) -> bool {
+            true
+        }
+        fn ensure_exit_node(&self, _: &str) -> TsHealth {
+            self.ts.clone()
+        }
+        fn tailscale_check(&self, _: &str) -> TsHealth {
+            self.ts.clone()
+        }
+        fn connectivity(&self, _: &Config) -> Connectivity {
+            self.conn.clone()
+        }
+        fn notify(&self, summary: &str, _: &str, _: Urgency) {
+            self.notes.borrow_mut().push(summary.to_string());
+        }
+        fn log(&self, _: &str) {}
+    }
+
+    fn with_profile(name: &str, p: Profile) -> Config {
+        let mut c = cfg();
+        c.profiles.insert(name.to_string(), p);
+        c
+    }
+
+    fn connected(o: &Outcome) -> (&str, &Option<String>) {
+        match o {
+            Outcome::Connected { ssid, note } => (ssid.as_str(), note),
+            other => panic!("expected Connected, got {other:?}"),
+        }
+    }
+
+    // --- flow::run state machine ---
+
+    #[test]
+    fn run_unknown_profile_returns_unknown_and_notifies() {
+        let be = Fake::new();
+        let o = run(&be, &cfg(), "ghost");
+        assert!(matches!(o, Outcome::UnknownProfile(p) if p == "ghost"));
+        assert!(be.notified("unknown profile"));
+    }
+
+    #[test]
+    fn run_no_interface_returns_no_interface() {
+        let be = Fake::new().no_iface();
+        let c = with_profile(
+            "home",
+            Profile {
+                networks: vec!["HomeWifi".into()],
+                ..Default::default()
+            },
+        );
+        assert!(matches!(run(&be, &c, "home"), Outcome::NoInterface));
+    }
+
+    #[test]
+    fn run_connects_to_visible_priority_network() {
+        let c = with_profile(
+            "home",
+            Profile {
+                networks: vec!["HomeWifi".into()],
+                ..Default::default()
+            },
+        );
+        let be = Fake::new()
+            .visible(&["HomeWifi", "CafeWifi"])
+            .connectable(&["HomeWifi"]);
+        let o = run(&be, &c, "home");
+        let (ssid, note) = connected(&o);
+        assert_eq!(ssid, "HomeWifi");
+        assert!(note.is_none());
+    }
+
+    #[test]
+    fn run_follows_priority_order() {
+        let c = with_profile(
+            "home",
+            Profile {
+                networks: vec!["WorkNet".into(), "HomeWifi".into()],
+                ..Default::default()
+            },
+        );
+        let be = Fake::new()
+            .visible(&["WorkNet", "HomeWifi"])
+            .connectable(&["WorkNet", "HomeWifi"]);
+        assert_eq!(connected(&run(&be, &c, "home")).0, "WorkNet");
+    }
+
+    #[test]
+    fn run_skips_failing_network_and_tries_next() {
+        let c = with_profile(
+            "home",
+            Profile {
+                networks: vec!["WorkNet".into(), "HomeWifi".into()],
+                ..Default::default()
+            },
+        );
+        let be = Fake::new()
+            .visible(&["WorkNet", "HomeWifi"])
+            .connectable(&["HomeWifi"]); // WorkNet fails
+        assert_eq!(connected(&run(&be, &c, "home")).0, "HomeWifi");
+    }
+
+    #[test]
+    fn run_no_networks_in_range_returns_no_networks() {
+        let c = with_profile(
+            "home",
+            Profile {
+                networks: vec!["HomeWifi".into()],
+                ..Default::default()
+            },
+        );
+        let be = Fake::new().visible(&["SomeoneElse"]);
+        assert!(matches!(run(&be, &c, "home"), Outcome::NoNetworks));
+        assert!(be.notified("no known networks"));
+    }
+
+    #[test]
+    fn run_captive_portal_surfaces_as_note() {
+        let c = with_profile(
+            "home",
+            Profile {
+                networks: vec!["HomeWifi".into()],
+                ..Default::default()
+            },
+        );
+        let be = Fake::new()
+            .visible(&["HomeWifi"])
+            .connectable(&["HomeWifi"])
+            .conn(Connectivity::Portal(Some("http://login.test".into())));
+        let o = run(&be, &c, "home");
+        let (_, note) = connected(&o);
+        assert!(note.as_ref().unwrap().contains("captive portal"));
+        assert!(note.as_ref().unwrap().contains("http://login.test"));
+    }
+
+    #[test]
+    fn run_offline_after_associate_is_degraded_note() {
+        let c = with_profile(
+            "home",
+            Profile {
+                networks: vec!["HomeWifi".into()],
+                ..Default::default()
+            },
+        );
+        let be = Fake::new()
+            .visible(&["HomeWifi"])
+            .connectable(&["HomeWifi"])
+            .conn(Connectivity::Offline);
+        let o = run(&be, &c, "home");
+        let (_, note) = connected(&o);
+        assert!(note.as_ref().unwrap().contains("no internet"));
+    }
+
+    #[test]
+    fn run_tailscale_gated_moves_to_target_when_healthy() {
+        let c = with_profile(
+            "work",
+            Profile {
+                bootstrap: Some("CafeWifi".into()),
+                networks: vec!["WorkNet".into()],
+                tailscale: true,
+                ..Default::default()
+            },
+        );
+        let be = Fake::new()
+            .visible(&["CafeWifi", "WorkNet"])
+            .connectable(&["CafeWifi", "WorkNet"])
+            .ts(TsHealth::Ok);
+        assert_eq!(connected(&run(&be, &c, "work")).0, "WorkNet");
+    }
+
+    #[test]
+    fn run_tailscale_unhealthy_stays_on_bootstrap() {
+        let c = with_profile(
+            "work",
+            Profile {
+                bootstrap: Some("CafeWifi".into()),
+                networks: vec!["WorkNet".into()],
+                tailscale: true,
+                ..Default::default()
+            },
+        );
+        let be = Fake::new()
+            .visible(&["CafeWifi", "WorkNet"])
+            .connectable(&["CafeWifi", "WorkNet"])
+            .ts(TsHealth::NeedsLogin);
+        match run(&be, &c, "work") {
+            Outcome::TailscaleError { ssid, health } => {
+                assert_eq!(ssid.as_deref(), Some("CafeWifi"));
+                assert_eq!(health, TsHealth::NeedsLogin);
+            }
+            other => panic!("expected TailscaleError, got {other:?}"),
+        }
+        assert!(be.notified("Tailscale"));
+    }
+
+    #[test]
+    fn run_tailscale_ok_but_target_out_of_range_keeps_bootstrap() {
+        let c = with_profile(
+            "work",
+            Profile {
+                bootstrap: Some("CafeWifi".into()),
+                networks: vec!["WorkNet".into()],
+                tailscale: true,
+                ..Default::default()
+            },
+        );
+        let be = Fake::new()
+            .visible(&["CafeWifi"]) // WorkNet not in range
+            .connectable(&["CafeWifi"])
+            .ts(TsHealth::Ok);
+        let o = run(&be, &c, "work");
+        let (ssid, note) = connected(&o);
+        assert_eq!(ssid, "CafeWifi");
+        assert!(note.as_ref().unwrap().contains("not in range"));
+    }
+
+    // --- Outcome::ok ---
+
+    #[test]
+    fn outcome_ok_true_for_connected_with_and_without_note() {
+        assert!(Outcome::Connected {
+            ssid: "x".into(),
+            note: None
+        }
+        .ok());
+        assert!(Outcome::Connected {
+            ssid: "x".into(),
+            note: Some("associated but no internet yet".into()),
+        }
+        .ok());
+    }
+
+    #[test]
+    fn outcome_ok_false_for_all_error_variants() {
+        assert!(!Outcome::NoInterface.ok());
+        assert!(!Outcome::NoNetworks.ok());
+        assert!(!Outcome::UnknownProfile("p".into()).ok());
+        assert!(!Outcome::TailscaleError {
+            ssid: None,
+            health: TsHealth::NeedsLogin,
+        }
+        .ok());
+        assert!(!Outcome::TailscaleError {
+            ssid: Some("boot".into()),
+            health: TsHealth::ExitNodeOffline,
+        }
+        .ok());
+    }
+
+    // --- resolve_candidates ---
+
     #[test]
     fn candidates_follow_priority_order() {
         let c = cfg();
@@ -345,4 +688,50 @@ mod tests {
             .collect();
         assert_eq!(got, vec!["WorkNet"]);
     }
+
+    #[test]
+    fn candidates_empty_when_profile_has_no_networks() {
+        let c = cfg();
+        let p = Profile::default();
+        assert!(resolve_candidates(&c, &p).is_empty());
+    }
+
+    #[test]
+    fn candidates_include_all_known_only_no_explicit_networks() {
+        let c = cfg();
+        let p = Profile {
+            include_all_known: true,
+            ..Default::default()
+        };
+        let got: Vec<&str> = resolve_candidates(&c, &p)
+            .iter()
+            .map(|n| n.ssid.as_str())
+            .collect();
+        assert_eq!(got.len(), 4);
+        assert_eq!(got[0], "HomeWifi");
+    }
+
+    #[test]
+    fn candidates_deduplicates_repeated_ssid_in_explicit_list() {
+        let c = cfg();
+        let p = Profile {
+            networks: vec!["HomeWifi".into(), "HomeWifi".into(), "WorkNet".into()],
+            ..Default::default()
+        };
+        let got: Vec<&str> = resolve_candidates(&c, &p)
+            .iter()
+            .map(|n| n.ssid.as_str())
+            .collect();
+        assert_eq!(got, vec!["HomeWifi", "WorkNet"]);
+    }
+
+    #[test]
+    fn candidates_all_unknown_ssids_returns_empty() {
+        let c = cfg();
+        let p = Profile {
+            networks: vec!["Ghost1".into(), "Ghost2".into()],
+            ..Default::default()
+        };
+        assert!(resolve_candidates(&c, &p).is_empty());
+    }
 }

src/main.rs

@@ -1,3 +1,4 @@
+mod backend;
 mod config;
 mod flow;
 mod nm;
@@ -14,6 +15,7 @@ use std::time::Duration;
 
 use clap::{Parser, Subcommand};
 
+use backend::Backend;
 use config::{Config, NetworkDef};
 use state::State;
 use util::{command_exists, home_dir, run};
@@ -44,7 +46,11 @@ struct Cli {
 #[derive(Subcommand)]
 enum Cmd {
     /// Show current Wi-Fi / profile / Tailscale status (default)
-    Status,
+    Status {
+        /// Emit machine-readable JSON instead of the human summary
+        #[arg(long)]
+        json: bool,
+    },
     /// Run the full connect sequence for the active profile
     #[command(visible_aliases = ["up", "connect", "i"])]
     Init,
@@ -126,6 +132,15 @@ enum ProfileCmd {
     },
     /// List available profiles
     List,
+    /// Create a new (empty) profile
+    Add {
+        name: String,
+        /// SSID whose presence marks this location (repeatable, for `detect`)
+        #[arg(long = "detect")]
+        detect: Vec<String>,
+    },
+    /// Delete a profile (core profiles home/work/away cannot be removed)
+    Remove { name: String },
 }
 
 fn main() {
@@ -148,7 +163,7 @@ fn active_profile(cfg: &Config, override_p: &Option<String>) -> String {
 }
 
 fn real_main(cli: Cli) -> Result<i32, String> {
-    let cmd = cli.cmd.unwrap_or(Cmd::Status);
+    let cmd = cli.cmd.unwrap_or(Cmd::Status { json: false });
 
     // `cd` and `install-service` don't need a parsed config first.
     if let Cmd::Cd { shell } = &cmd {
@@ -156,18 +171,19 @@ fn real_main(cli: Cli) -> Result<i32, String> {
     }
 
     let mut cfg = Config::load()?;
+    let be = backend::System;
 
     match cmd {
-        Cmd::Status => cmd_status(&cfg, &cli.profile),
+        Cmd::Status { json } => cmd_status(&be, &cfg, &cli.profile, json),
         Cmd::Init => {
             let p = active_profile(&cfg, &cli.profile);
-            let outcome = flow::run(&cfg, &p);
+            let outcome = flow::run(&be, &cfg, &p);
             print_outcome(&p, &outcome);
             Ok(if outcome.ok() { 0 } else { 1 })
         }
         Cmd::Watch { no_initial } => Ok(watch::run(cfg, !no_initial)),
-        Cmd::Profile { action } => cmd_profile(&cfg, action),
+        Cmd::Profile { action } => cmd_profile(&be, &mut cfg, action),
-        Cmd::Detect { apply } => cmd_detect(&cfg, apply),
+        Cmd::Detect { apply } => cmd_detect(&be, &cfg, apply),
         Cmd::Add {
             ssid,
             password,
@@ -179,7 +195,7 @@ fn real_main(cli: Cli) -> Result<i32, String> {
         Cmd::Scan { to } => cmd_scan(&mut cfg, to),
         Cmd::List { show_passwords } => cmd_list(&cfg, show_passwords),
         Cmd::Edit => cmd_edit(),
-        Cmd::Doctor { full } => cmd_doctor(&cfg, &cli.profile, full),
+        Cmd::Doctor { full } => cmd_doctor(&be, &cfg, &cli.profile, full),
         Cmd::InstallService { no_enable } => cmd_install_service(!no_enable),
         Cmd::Cd { .. } => unreachable!(),
     }
@@ -213,9 +229,45 @@ fn print_outcome(profile: &str, o: &flow::Outcome) {
     }
 }
 
-fn cmd_status(cfg: &Config, override_p: &Option<String>) -> Result<i32, String> {
+fn status_healthy(s: &status::Status) -> bool {
+    s.internet
+        && s.iface.is_some()
+        && (!s.tailscale_required || s.tailscale.as_ref().map(|h| h.is_ok()).unwrap_or(false))
+}
+
+fn cmd_status(
+    be: &dyn Backend,
+    cfg: &Config,
+    override_p: &Option<String>,
+    json: bool,
+) -> Result<i32, String> {
     let p = active_profile(cfg, override_p);
-    let s = status::gather(cfg, &p);
+    let s = status::gather(be, cfg, &p);
+    let healthy = status_healthy(&s);
+
+    if json {
+        let v = serde_json::json!({
+            "profile": p,
+            "adapter": s.iface,
+            "ssid": s.ssid,
+            "ip": s.ip,
+            "internet": s.internet,
+            "captive_portal": s.portal,
+            "tailscale": {
+                "required": s.tailscale_required,
+                "installed": s.tailscale.is_some(),
+                "ok": s.tailscale.as_ref().map(|h| h.is_ok()),
+                "health": s.tailscale.as_ref().map(|h| h.describe()),
+                "exit_node": s.exit_node,
+            },
+            "healthy": healthy,
+        });
+        println!(
+            "{}",
+            serde_json::to_string_pretty(&v).unwrap_or_else(|_| "{}".into())
+        );
+        return Ok(if healthy { 0 } else { 1 });
+    }
 
     let dot = |ok: bool| {
         if ok {
@@ -248,6 +300,14 @@ fn cmd_status(cfg: &Config, override_p: &Option<String>) -> Result<i32, String>
         dot(s.internet),
         if s.internet { "ok" } else { "down" }
     );
+    if let Some(portal) = &s.portal {
+        let detail = if portal.is_empty() {
+            "sign-in required".to_string()
+        } else {
+            portal.clone()
+        };
+        println!("  portal      {C_YELLOW}captive portal{C_RESET} {C_DIM}{detail}{C_RESET}");
+    }
 
     match (&s.tailscale, s.tailscale_required) {
         (Some(h), req) => {
@@ -263,9 +323,6 @@ fn cmd_status(cfg: &Config, override_p: &Option<String>) -> Result<i32, String>
         (None, _) => println!("  tailscale   {C_DIM}not installed{C_RESET}"),
     }
 
-    let healthy = s.internet
-        && s.iface.is_some()
-        && (!s.tailscale_required || s.tailscale.as_ref().map(|h| h.is_ok()).unwrap_or(false));
     println!(
         "  state       {}",
         if healthy {
@@ -277,7 +334,13 @@ fn cmd_status(cfg: &Config, override_p: &Option<String>) -> Result<i32, String>
     Ok(if healthy { 0 } else { 1 })
 }
 
-fn cmd_profile(cfg: &Config, action: Option<ProfileCmd>) -> Result<i32, String> {
+const CORE_PROFILES: [&str; 3] = ["home", "work", "away"];
+
+fn cmd_profile(
+    be: &dyn Backend,
+    cfg: &mut Config,
+    action: Option<ProfileCmd>,
+) -> Result<i32, String> {
     match action.unwrap_or(ProfileCmd::Get) {
         ProfileCmd::Get => {
             println!("{}", State::load(&cfg.settings.default_profile).profile);
@@ -291,6 +354,34 @@ fn cmd_profile(cfg: &Config, action: Option<ProfileCmd>) -> Result<i32, String>
             }
             Ok(0)
         }
+        ProfileCmd::Add { name, detect } => {
+            if cfg.profiles.contains_key(&name) {
+                return Err(format!("profile '{name}' already exists"));
+            }
+            cfg.profiles.insert(
+                name.clone(),
+                config::Profile {
+                    detect_ssids: detect,
+                    ..Default::default()
+                },
+            );
+            cfg.save()?;
+            println!("{C_GREEN}added{C_RESET} profile {name}");
+            Ok(0)
+        }
+        ProfileCmd::Remove { name } => {
+            if CORE_PROFILES.contains(&name.as_str()) {
+                return Err(format!(
+                    "'{name}' is a core profile and is always recreated; clear its networks instead"
+                ));
+            }
+            if cfg.profiles.remove(&name).is_none() {
+                return Err(format!("unknown profile '{name}'"));
+            }
+            cfg.save()?;
+            println!("{C_GREEN}removed{C_RESET} profile {name}");
+            Ok(0)
+        }
         ProfileCmd::Set { name, no_apply } => {
             if !cfg.profiles.contains_key(&name) {
                 let avail: Vec<&String> = cfg.profiles.keys().collect();
@@ -306,40 +397,46 @@ fn cmd_profile(cfg: &Config, action: Option<ProfileCmd>) -> Result<i32, String>
             if no_apply {
                 return Ok(0);
             }
-            let outcome = flow::run(cfg, &name);
+            let outcome = flow::run(be, cfg, &name);
             print_outcome(&name, &outcome);
             Ok(if outcome.ok() { 0 } else { 1 })
         }
     }
 }
 
-fn detect_profile(cfg: &Config) -> Option<String> {
+fn detect_profile(be: &dyn Backend, cfg: &Config) -> Option<String> {
-    let iface = nm::wifi_interface()?;
+    let iface = be.wifi_interface()?;
-    nm::radio_on();
+    be.radio_on();
-    nm::rescan(&iface, &[]);
+    be.rescan(&iface, &[]);
-    let visible = nm::visible_ssids(&iface);
+    let visible = be.visible_ssids(&iface);
 
-    // Profiles are stored in a BTreeMap so iteration order is deterministic
+    // Pick the profile with the most marker SSIDs in range, so overlapping
-    // (alphabetical). The caller can rely on that for tie-breaking.
+    // locations disambiguate by strength of evidence. Profiles iterate in
+    // BTreeMap (alphabetical) order, which deterministically breaks ties.
+    let mut best: Option<(usize, String)> = None;
     for (name, profile) in &cfg.profiles {
-        if profile.detect_ssids.is_empty() {
+        let score = profile
-            continue;
-        }
-        if profile
             .detect_ssids
             .iter()
-            .any(|s| visible.contains(s.as_str()))
+            .filter(|s| visible.contains(s.as_str()))
-        {
+            .count();
-            return Some(name.clone());
+        if score == 0 {
+            continue;
+        }
+        if best.as_ref().map(|(s, _)| score > *s).unwrap_or(true) {
+            best = Some((score, name.clone()));
         }
     }
 
     // Fall back to the default profile if no markers matched.
-    Some(cfg.settings.default_profile.clone())
+    Some(
+        best.map(|(_, name)| name)
+            .unwrap_or_else(|| cfg.settings.default_profile.clone()),
+    )
 }
 
-fn cmd_detect(cfg: &Config, apply: bool) -> Result<i32, String> {
+fn cmd_detect(be: &dyn Backend, cfg: &Config, apply: bool) -> Result<i32, String> {
-    match detect_profile(cfg) {
+    match detect_profile(be, cfg) {
         Some(p) => {
             println!("{p}");
             if apply {
@@ -348,7 +445,7 @@ fn cmd_detect(cfg: &Config, apply: bool) -> Result<i32, String> {
                     updated: util::timestamp(),
                 }
                 .save()?;
-                let outcome = flow::run(cfg, &p);
+                let outcome = flow::run(be, cfg, &p);
                 print_outcome(&p, &outcome);
                 return Ok(if outcome.ok() { 0 } else { 1 });
             }
@@ -497,10 +594,14 @@ fn cmd_scan(cfg: &mut Config, to: Option<String>) -> Result<i32, String> {
 }
 
 fn mask(p: &str) -> String {
-    if p.len() <= 2 {
+    // Count by characters, not bytes: slicing &p[..1] would panic on a
+    // multi-byte first character (valid in WPA passphrases).
+    let count = p.chars().count();
+    if count <= 2 {
         "••".into()
     } else {
-        format!("{}{}", &p[..1], "•".repeat(p.len().saturating_sub(1)))
+        let first: String = p.chars().take(1).collect();
+        format!("{}{}", first, "•".repeat(count - 1))
     }
 }
 
@@ -573,7 +674,12 @@ fn cmd_edit() -> Result<i32, String> {
     }
 }
 
-fn cmd_doctor(cfg: &Config, override_p: &Option<String>, full: bool) -> Result<i32, String> {
+fn cmd_doctor(
+    be: &dyn Backend,
+    cfg: &Config,
+    override_p: &Option<String>,
+    full: bool,
+) -> Result<i32, String> {
     if full {
         let script = config::config_dir().join("diag.sh");
         if !script.exists() {
@@ -590,7 +696,7 @@ fn cmd_doctor(cfg: &Config, override_p: &Option<String>, full: bool) -> Result<i
     }
 
     let p = active_profile(cfg, override_p);
-    let s = status::gather(cfg, &p);
+    let s = status::gather(be, cfg, &p);
     println!("{C_BOLD}breadcrumbs doctor{C_RESET}  (profile {p})");
     println!(
         "  nmcli       {}",

src/nm.rs

@@ -1,8 +1,9 @@
 use std::collections::HashSet;
+use std::path::PathBuf;
 use std::time::Duration;
 
-use crate::config::NetworkDef;
+use crate::config::{state_dir, NetworkDef};
-use crate::util::{run, run_ok};
+use crate::util::{run, run_ok, run_with_stdin};
 
 /// nmcli `-t` escapes `:` and `\` in field values; undo that.
 fn unescape(s: &str) -> String {
@@ -240,6 +241,19 @@ fn enforce_dns(uuid: &str, iface: &str, dns: &str) {
     }
 }
 
+/// Return true if `name` is NetworkManager's numbered-duplicate convention for
+/// `ssid`: exactly `ssid` followed by a space and one or more decimal digits
+/// (e.g. "MyNet 1", "MyNet 2"). A name like "MyNet1" (no space) is a distinct
+/// SSID and must not match.
+fn is_numbered_nm_duplicate(name: &str, ssid: &str) -> bool {
+    if let Some(suffix) = name.strip_prefix(ssid) {
+        if let Some(digits) = suffix.strip_prefix(' ') {
+            return !digits.is_empty() && digits.chars().all(|c| c.is_ascii_digit());
+        }
+    }
+    false
+}
+
 /// Return the name of the first saved NM connection profile whose name is
 /// either exactly `ssid` or `ssid N` (NM's numbered-duplicate convention).
 /// Returns `None` if no such profile exists.
@@ -254,26 +268,58 @@ fn first_profile_for_ssid(ssid: &str) -> Option<String> {
     }
     let mut fallback: Option<String> = None;
     for line in o.stdout.lines() {
-        let parts: Vec<&str> = line.splitn(2, ':').collect();
+        // NAME may itself contain an (escaped) ':', so a plain splitn would
-        if parts.len() < 2 || !parts[1].contains("wireless") {
+        // mis-split it — parse the line the same way nmcli escapes it.
+        let fields = parse_scan_line(line);
+        if fields.len() < 2 || !fields[1].contains("wireless") {
             continue;
         }
-        let name = unescape(parts[0]);
+        let name = fields[0].clone();
         if name == ssid {
             return Some(name);
         }
-        if fallback.is_none() {
+        if fallback.is_none() && is_numbered_nm_duplicate(&name, ssid) {
-            if let Some(suffix) = name.strip_prefix(ssid) {
+            fallback = Some(name);
-                let s = suffix.trim();
-                if !s.is_empty() && s.chars().all(|c| c.is_ascii_digit()) {
-                    fallback = Some(name);
-                }
-            }
         }
     }
     fallback
 }
 
+/// Write the PSK to a 0600 file in the `setting.property:value` format nmcli's
+/// `passwd-file` expects, so the secret reaches NetworkManager without ever
+/// appearing in argv (where any local user could read it via `ps`). Returns the
+/// path; the caller is responsible for removing it.
+fn write_psk_file(password: &str) -> Option<PathBuf> {
+    use std::io::Write;
+    // Prefer $XDG_RUNTIME_DIR (per-user tmpfs, mode 0700, wiped on logout) for a
+    // transient secret; fall back to the on-disk state dir only if it's unset.
+    let dir = std::env::var_os("XDG_RUNTIME_DIR")
+        .map(PathBuf::from)
+        .unwrap_or_else(state_dir);
+    let _ = std::fs::create_dir_all(&dir);
+    let path = dir.join(format!("breadcrumbs.psk.{}", std::process::id()));
+    let mut f = {
+        #[cfg(unix)]
+        {
+            use std::os::unix::fs::OpenOptionsExt;
+            std::fs::OpenOptions::new()
+                .write(true)
+                .create(true)
+                .truncate(true)
+                .mode(0o600)
+                .open(&path)
+                .ok()?
+        }
+        #[cfg(not(unix))]
+        {
+            std::fs::File::create(&path).ok()?
+        }
+    };
+    f.write_all(format!("802-11-wireless-security.psk:{password}\n").as_bytes())
+        .ok()?;
+    Some(path)
+}
+
 /// Connect to a network and pin DNS. Returns true only if associated.
 pub fn connect(iface: &str, net: &NetworkDef, wait: u32, dns: &str) -> bool {
     connect_verbose(iface, net, wait, dns).is_ok()
@@ -290,20 +336,8 @@ pub fn connect_verbose(iface: &str, net: &NetworkDef, wait: u32, dns: &str) -> R
     let wait_s = wait.to_string();
 
     if let Some(profile) = first_profile_for_ssid(&net.ssid) {
-        // Update the saved PSK and, for hidden networks, ensure the flag is set.
+        // Ensure the hidden flag is set — this carries no secret, so passing it
-        if !net.password.is_empty() {
+        // in argv is safe.
-            let _ = run(
-                "nmcli",
-                &[
-                    "connection",
-                    "modify",
-                    &profile,
-                    "802-11-wireless-security.psk",
-                    net.password.as_str(),
-                ],
-                Duration::from_secs(6),
-            );
-        }
         if net.hidden {
             let _ = run(
                 "nmcli",
@@ -317,50 +351,64 @@ pub fn connect_verbose(iface: &str, net: &NetworkDef, wait: u32, dns: &str) -> R
                 Duration::from_secs(6),
             );
         }
-        let o = run(
+        // Supply the PSK to the activation via a 0600 passwd-file rather than
-            "nmcli",
+        // argv. Harmless if NM already has a matching secret stored.
-            &[
+        let psk_file = if net.password.is_empty() {
-                "--wait",
+            None
-                &wait_s,
+        } else {
-                "connection",
+            write_psk_file(&net.password)
-                "up",
+        };
-                &profile,
+        let psk_path = psk_file.as_ref().map(|p| p.display().to_string());
-                "ifname",
+        let mut args: Vec<&str> = vec![
-                iface,
+            "--wait",
-            ],
+            &wait_s,
-            Duration::from_secs(wait as u64 + 15),
+            "connection",
-        );
+            "up",
-        if !o.success {
+            &profile,
-            let detail = o.stderr.trim().to_string();
+            "ifname",
-            return Err(if detail.is_empty() {
+            iface,
-                o.stdout.trim().to_string()
+        ];
-            } else {
+        if let Some(ref p) = psk_path {
-                detail
+            args.push("passwd-file");
-            });
+            args.push(p.as_str());
         }
-        if let Some(uuid) = active_uuid(iface) {
+        let o = run("nmcli", &args, Duration::from_secs(wait as u64 + 15));
-            enforce_dns(&uuid, iface, dns);
+        if let Some(p) = psk_file {
+            let _ = std::fs::remove_file(p);
         }
-        return Ok(());
+        if o.success {
+            if let Some(uuid) = active_uuid(iface) {
+                enforce_dns(&uuid, iface, dns);
+            }
+            return Ok(());
+        }
+        // Activation failed (e.g. the saved secret is stale). Fall through to a
+        // fresh connect below, which re-supplies the PSK over stdin.
     }
 
-    // No saved profile — create one via device wifi connect.
+    // No saved profile (or reuse failed) — create/refresh via device wifi
+    // connect. `--ask` makes nmcli read the PSK from stdin instead of argv.
     let hidden = if net.hidden { "yes" } else { "no" };
     let args = [
+        "--ask",
         "--wait",
         &wait_s,
         "device",
         "wifi",
         "connect",
         net.ssid.as_str(),
-        "password",
-        net.password.as_str(),
         "hidden",
         hidden,
         "ifname",
         iface,
     ];
-    let o = run("nmcli", &args, Duration::from_secs(wait as u64 + 15));
+    let stdin = format!("{}\n", net.password);
+    let o = run_with_stdin(
+        "nmcli",
+        &args,
+        Some(&stdin),
+        Duration::from_secs(wait as u64 + 15),
+    );
     if !o.success {
         let detail = o.stderr.trim().to_string();
         return Err(if detail.is_empty() {
@@ -388,15 +436,12 @@ pub fn delete_connections_for_ssid(ssid: &str) -> bool {
     }
     let mut removed = false;
     for line in list.stdout.lines() {
-        let parts: Vec<&str> = line.splitn(2, ':').collect();
+        // NAME may contain an escaped ':' — parse rather than naive-split.
-        if parts.len() < 2 {
+        let fields = parse_scan_line(line);
-            continue;
+        if fields.len() < 2 || !fields[1].contains("wireless") {
-        }
-        let name = unescape(parts[0]);
-        let typ = parts[1];
-        if !typ.contains("wireless") {
             continue;
         }
+        let name = fields[0].clone();
         let conn_ssid = run(
             "nmcli",
             &["-g", "802-11-wireless.ssid", "connection", "show", &name],
@@ -428,6 +473,21 @@ mod tests {
         assert_eq!(unescape("trailing\\"), "trailing\\");
     }
 
+    #[test]
+    fn unescape_empty_string() {
+        assert_eq!(unescape(""), "");
+    }
+
+    #[test]
+    fn unescape_multiple_consecutive_escapes() {
+        assert_eq!(unescape(r"a\:b\:c"), "a:b:c");
+    }
+
+    #[test]
+    fn unescape_double_backslash_produces_single() {
+        assert_eq!(unescape(r"a\\b"), r"a\b");
+    }
+
     #[test]
     fn parse_scan_line_splits_and_unescapes() {
         // SSID:SIGNAL:SECURITY with an escaped ':' inside the SSID.
@@ -442,4 +502,71 @@ mod tests {
         let f = parse_scan_line(":40:WPA3");
         assert_eq!(f, vec!["", "40", "WPA3"]);
     }
+
+    #[test]
+    fn parse_scan_line_single_field_no_separators() {
+        let f = parse_scan_line("OnlySSID");
+        assert_eq!(f, vec!["OnlySSID"]);
+    }
+
+    #[test]
+    fn parse_scan_line_empty_input_yields_one_empty_field() {
+        let f = parse_scan_line("");
+        assert_eq!(f, vec![""]);
+    }
+
+    #[test]
+    fn parse_scan_line_all_empty_fields() {
+        // Three colons → four empty fields.
+        let f = parse_scan_line(":::");
+        assert_eq!(f, vec!["", "", "", ""]);
+    }
+
+    #[test]
+    fn parse_scan_line_multiple_escaped_colons_in_ssid() {
+        let f = parse_scan_line(r"a\:b\:c:80:WPA3");
+        assert_eq!(f, vec!["a:b:c", "80", "WPA3"]);
+    }
+
+    #[test]
+    fn parse_scan_line_backslash_escape_then_colon_separator() {
+        // "abc\:60:WPA2" — \: is an escaped colon inside the SSID, not a separator.
+        let f = parse_scan_line(r"abc\:60:WPA2");
+        assert_eq!(f, vec!["abc:60", "WPA2"]);
+    }
+
+    #[test]
+    fn is_numbered_nm_duplicate_exact_match_is_not_duplicate() {
+        assert!(!is_numbered_nm_duplicate("Net", "Net"));
+    }
+
+    #[test]
+    fn is_numbered_nm_duplicate_space_digits_matches() {
+        assert!(is_numbered_nm_duplicate("Net 1", "Net"));
+        assert!(is_numbered_nm_duplicate("My Network 12", "My Network"));
+    }
+
+    #[test]
+    fn is_numbered_nm_duplicate_no_space_does_not_match() {
+        // "Net1" is a distinct SSID, not a numbered duplicate of "Net".
+        assert!(!is_numbered_nm_duplicate("Net1", "Net"));
+        assert!(!is_numbered_nm_duplicate("HomeWifi2", "HomeWifi"));
+    }
+
+    #[test]
+    fn is_numbered_nm_duplicate_non_numeric_suffix_does_not_match() {
+        assert!(!is_numbered_nm_duplicate("Net foo", "Net"));
+        assert!(!is_numbered_nm_duplicate("Net 1x", "Net"));
+    }
+
+    #[test]
+    fn is_numbered_nm_duplicate_empty_digits_does_not_match() {
+        // "Net " (trailing space only, no digits) must not match.
+        assert!(!is_numbered_nm_duplicate("Net ", "Net"));
+    }
+
+    #[test]
+    fn is_numbered_nm_duplicate_unrelated_name_does_not_match() {
+        assert!(!is_numbered_nm_duplicate("OtherNet 1", "Net"));
+    }
 }

src/state.rs

@@ -29,6 +29,7 @@ impl State {
     pub fn save(&self) -> Result<(), String> {
         fs::create_dir_all(state_dir()).map_err(|e| format!("creating state dir: {e}"))?;
         let text = toml::to_string_pretty(self).map_err(|e| format!("serializing state: {e}"))?;
-        fs::write(state_path(), text).map_err(|e| format!("writing state: {e}"))
+        crate::util::write_atomic(&state_path(), &text, 0o644)
+            .map_err(|e| format!("writing state: {e}"))
     }
 }

src/status.rs

@@ -1,11 +1,31 @@
 use std::time::Duration;
 
+use crate::backend::Backend;
 use crate::config::Config;
-use crate::nm;
+use crate::tailscale::TsHealth;
-use crate::tailscale::{self, TsHealth};
 use crate::util::{command_exists, run};
 
-pub fn internet_ok(cfg: &Config) -> bool {
+/// Result of a connectivity probe. `Portal` distinguishes a captive portal
+/// (associated, but traffic is being intercepted) from real internet or a hard
+/// outage — the optional string is the portal's sign-in URL when known.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum Connectivity {
+    Online,
+    Portal(Option<String>),
+    Offline,
+}
+
+impl Connectivity {
+    pub fn online(&self) -> bool {
+        matches!(self, Connectivity::Online)
+    }
+}
+
+/// Probe connectivity. Only an empty HTTP 204 from the generate_204-style
+/// endpoint counts as online; a 200/redirect means a captive portal is
+/// intercepting traffic. If the HTTP probe is inconclusive (timeout/5xx) we fall
+/// back to ICMP, which reaching the host treats as online.
+pub fn connectivity(cfg: &Config) -> Connectivity {
     if command_exists("curl") {
         let o = run(
             "curl",
@@ -14,28 +34,45 @@ pub fn internet_ok(cfg: &Config) -> bool {
                 "-o",
                 "/dev/null",
                 "-w",
-                "%{http_code}",
+                "%{http_code} %{redirect_url}",
                 "--max-time",
                 "4",
                 &cfg.settings.connectivity_url,
             ],
             Duration::from_secs(6),
         );
-        let code = o.stdout.trim();
+        let mut parts = o.stdout.split_whitespace();
-        if code == "204" || code == "200" || code == "301" || code == "302" {
+        let code = parts.next().unwrap_or("");
-            return true;
+        let redirect = parts.next().unwrap_or("").trim();
+        match code {
+            "204" => return Connectivity::Online,
+            "200" | "301" | "302" | "303" | "307" | "308" => {
+                let url = if redirect.is_empty() {
+                    None
+                } else {
+                    Some(redirect.to_string())
+                };
+                return Connectivity::Portal(url);
+            }
+            // 000/timeout/5xx → inconclusive, try ICMP below.
+            _ => {}
         }
     }
-    // Fallback: ICMP to the configured host.
+    let ping = run(
-    run(
         "ping",
         &["-c", "1", "-W", "2", &cfg.settings.ping_host],
         Duration::from_secs(4),
     )
-    .success
+    .success;
+    if ping {
+        Connectivity::Online
+    } else {
+        Connectivity::Offline
+    }
 }
 
-fn ipv4(iface: &str) -> Option<String> {
+/// Best-effort IPv4 address of `iface` via nmcli, with the CIDR prefix stripped.
+pub fn ipv4(iface: &str) -> Option<String> {
     let o = run(
         "nmcli",
         &["-g", "IP4.ADDRESS", "device", "show", iface],
@@ -48,7 +85,9 @@ fn ipv4(iface: &str) -> Option<String> {
     if s.is_empty() {
         None
     } else {
-        Some(s.lines().next().unwrap_or(s).trim().to_string())
+        // nmcli reports "192.168.1.5/24"; drop the prefix length for display.
+        let first = s.lines().next().unwrap_or(s).trim();
+        Some(first.split('/').next().unwrap_or(first).to_string())
     }
 }
 
@@ -57,16 +96,24 @@ pub struct Status {
     pub ssid: Option<String>,
     pub ip: Option<String>,
     pub internet: bool,
+    /// Set when a captive portal was detected; inner string is its URL if known.
+    pub portal: Option<String>,
     pub tailscale_required: bool,
     pub tailscale: Option<TsHealth>,
     pub exit_node: String,
 }
 
-pub fn gather(cfg: &Config, profile_name: &str) -> Status {
+pub fn gather(be: &dyn Backend, cfg: &Config, profile_name: &str) -> Status {
-    let iface = nm::wifi_interface();
+    let iface = be.wifi_interface();
-    let ssid = iface.as_deref().and_then(nm::active_ssid);
+    let ssid = iface.as_deref().and_then(|i| be.active_ssid(i));
-    let ip = iface.as_deref().and_then(ipv4);
+    let ip = iface.as_deref().and_then(|i| be.ipv4(i));
-    let internet = internet_ok(cfg);
+
+    let conn = be.connectivity(cfg);
+    let internet = conn.online();
+    let portal = match conn {
+        Connectivity::Portal(url) => Some(url.unwrap_or_default()),
+        _ => None,
+    };
 
     let prof = cfg.profile(profile_name);
     let ts_required = prof.map(|p| p.tailscale).unwrap_or(false);
@@ -74,8 +121,8 @@ pub fn gather(cfg: &Config, profile_name: &str) -> Status {
         .and_then(|p| p.exit_node.clone())
         .unwrap_or_else(|| cfg.settings.exit_node.clone());
 
-    let tailscale = if tailscale::installed() {
+    let tailscale = if be.tailscale_installed() {
-        Some(tailscale::check(&exit_node))
+        Some(be.tailscale_check(&exit_node))
     } else {
         None
     };
@@ -85,6 +132,7 @@ pub fn gather(cfg: &Config, profile_name: &str) -> Status {
         ssid,
         ip,
         internet,
+        portal,
         tailscale_required: ts_required,
         tailscale,
         exit_node,

src/tailscale.rs

@@ -313,6 +313,54 @@ mod tests {
     use super::*;
     use serde_json::json;
 
+    #[test]
+    fn ts_health_is_ok_only_for_ok_variant() {
+        assert!(TsHealth::Ok.is_ok());
+        assert!(!TsHealth::NotInstalled.is_ok());
+        assert!(!TsHealth::NeedsLogin.is_ok());
+        assert!(!TsHealth::Stopped.is_ok());
+        assert!(!TsHealth::ExitNodeMissing.is_ok());
+        assert!(!TsHealth::ExitNodeOffline.is_ok());
+        assert!(!TsHealth::Error("x".into()).is_ok());
+    }
+
+    #[test]
+    fn ts_health_describe_covers_all_variants() {
+        assert_eq!(TsHealth::Ok.describe(), "ok");
+        assert!(TsHealth::NotInstalled.describe().contains("not installed"));
+        assert!(TsHealth::NeedsLogin.describe().contains("not logged in"));
+        assert!(TsHealth::Stopped.describe().contains("stopped"));
+        assert!(TsHealth::ExitNodeMissing.describe().contains("not found"));
+        assert!(TsHealth::ExitNodeOffline.describe().contains("offline"));
+        let msg = TsHealth::Error("boom".into()).describe();
+        assert!(msg.contains("boom"));
+    }
+
+    #[test]
+    fn extract_url_finds_https_url() {
+        assert_eq!(
+            extract_url("To authenticate, visit https://login.tailscale.com/a/xxx"),
+            Some("https://login.tailscale.com/a/xxx".into())
+        );
+    }
+
+    #[test]
+    fn extract_url_returns_none_when_no_url() {
+        assert_eq!(extract_url("Waiting for login..."), None);
+        assert_eq!(extract_url(""), None);
+    }
+
+    #[test]
+    fn extract_url_picks_first_https_token() {
+        let line = "Try https://first.example.com https://second.example.com";
+        assert_eq!(extract_url(line), Some("https://first.example.com".into()));
+    }
+
+    #[test]
+    fn extract_url_does_not_match_plain_http() {
+        assert_eq!(extract_url("see http://example.com for info"), None);
+    }
+
     #[test]
     fn backend_state_extraction() {
         assert_eq!(
@@ -322,6 +370,13 @@ mod tests {
         assert_eq!(backend_state(&json!({})), "");
     }
 
+    #[test]
+    fn backend_state_all_known_values() {
+        for state in ["Running", "NeedsLogin", "NoState", "Stopped"] {
+            assert_eq!(backend_state(&json!({"BackendState": state})), state);
+        }
+    }
+
     #[test]
     fn exit_node_healthy_and_selected() {
         let v = json!({
@@ -381,4 +436,59 @@ mod tests {
         });
         assert_eq!(exit_node_state(&v, "exitnode"), (true, true, false));
     }
+
+    #[test]
+    fn exit_node_state_empty_peer_map() {
+        let v = json!({ "BackendState": "Running", "Peer": {} });
+        assert_eq!(exit_node_state(&v, "anynode"), (false, false, false));
+    }
+
+    #[test]
+    fn exit_node_state_no_peer_field() {
+        let v = json!({ "BackendState": "Running" });
+        assert_eq!(exit_node_state(&v, "anynode"), (false, false, false));
+    }
+
+    #[test]
+    fn exit_node_state_case_insensitive_hostname() {
+        let v = json!({
+            "Peer": {
+                "k1": { "HostName": "MYNODE", "DNSName": "mynode.ts.net.",
+                        "Online": true, "ExitNode": true, "ExitNodeOption": true }
+            }
+        });
+        let (exists, online, selected) = exit_node_state(&v, "mynode");
+        assert!(exists && online && selected);
+    }
+
+    #[test]
+    fn exit_node_status_overrides_peer_online_when_selected() {
+        // ExitNodeStatus.Online=false should override the peer's Online=true
+        // when the peer is the currently-selected exit node.
+        let v = json!({
+            "ExitNodeStatus": { "Online": false },
+            "Peer": {
+                "k1": { "HostName": "exitnode", "DNSName": "exitnode.ts.net.",
+                        "Online": true, "ExitNode": true, "ExitNodeOption": true }
+            }
+        });
+        let (exists, online, selected) = exit_node_state(&v, "exitnode");
+        assert!(exists);
+        assert!(
+            !online,
+            "ExitNodeStatus.Online=false should override peer Online"
+        );
+        assert!(selected);
+    }
+
+    #[test]
+    fn exit_node_state_wrong_node_name_not_matched() {
+        let v = json!({
+            "Peer": {
+                "k1": { "HostName": "othernode", "DNSName": "othernode.ts.net.",
+                        "Online": true, "ExitNode": true, "ExitNodeOption": true }
+            }
+        });
+        assert_eq!(exit_node_state(&v, "exitnode"), (false, false, false));
+    }
 }

src/util.rs

@@ -1,5 +1,6 @@
+use std::fs;
 use std::io::{Read, Write};
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
 use std::process::{Command, Stdio};
 use std::thread;
 use std::time::{Duration, Instant, SystemTime, UNIX_EPOCH};
@@ -10,6 +11,42 @@ pub fn home_dir() -> PathBuf {
         .unwrap_or_else(|| PathBuf::from("/root"))
 }
 
+/// Atomically replace `path` with `contents`: write a sibling temp file (created
+/// with `mode` on unix) and `rename` it over the target. Avoids torn reads by a
+/// concurrent reader (the watch daemon reloads config every tick) and never
+/// leaves a half-written file behind on crash. Because the temp file is created
+/// with `mode` up front, secrets never exist world-readable even briefly.
+pub fn write_atomic(path: &Path, contents: &str, mode: u32) -> std::io::Result<()> {
+    let dir = path.parent().unwrap_or_else(|| Path::new("."));
+    fs::create_dir_all(dir)?;
+    let stem = path
+        .file_name()
+        .and_then(|s| s.to_str())
+        .unwrap_or("breadcrumbs");
+    let tmp = dir.join(format!(".{stem}.tmp.{}", std::process::id()));
+
+    let mut open = fs::OpenOptions::new();
+    open.write(true).create(true).truncate(true);
+    #[cfg(unix)]
+    {
+        use std::os::unix::fs::OpenOptionsExt;
+        open.mode(mode);
+    }
+    #[cfg(not(unix))]
+    let _ = mode;
+
+    let res = (|| {
+        let mut f = open.open(&tmp)?;
+        f.write_all(contents.as_bytes())?;
+        f.sync_all()?;
+        fs::rename(&tmp, path)
+    })();
+    if res.is_err() {
+        let _ = fs::remove_file(&tmp);
+    }
+    res
+}
+
 pub fn command_exists(name: &str) -> bool {
     if let Some(paths) = std::env::var_os("PATH") {
         for dir in std::env::split_paths(&paths) {
@@ -55,6 +92,11 @@ pub fn run_with_stdin(prog: &str, args: &[&str], stdin: Option<&str>, timeout: D
     };
     let mut child = match Command::new(prog)
         .args(args)
+        // Pin the C locale so message text we parse (nmcli states, monitor
+        // lines) is stable English regardless of the user's LANG. SSID/value
+        // bytes are unaffected.
+        .env("LC_ALL", "C")
+        .env("LANG", "C")
         .stdin(stdin_cfg)
         .stdout(Stdio::piped())
         .stderr(Stdio::piped())
@@ -64,13 +106,6 @@ pub fn run_with_stdin(prog: &str, args: &[&str], stdin: Option<&str>, timeout: D
         Err(_) => return Output::failed(),
     };
 
-    if let Some(data) = stdin {
-        if let Some(mut sink) = child.stdin.take() {
-            let _ = sink.write_all(data.as_bytes());
-            // Drop closes the pipe so the child's read sees EOF.
-        }
-    }
-
     let mut stdout_pipe = child.stdout.take();
     let mut stderr_pipe = child.stderr.take();
 
@@ -89,6 +124,16 @@ pub fn run_with_stdin(prog: &str, args: &[&str], stdin: Option<&str>, timeout: D
         buf
     });
 
+    // Feed stdin only after the reader threads are draining stdout/stderr, so a
+    // child that writes more than a pipe buffer before consuming stdin can't
+    // deadlock against our blocking write.
+    if let Some(data) = stdin {
+        if let Some(mut sink) = child.stdin.take() {
+            let _ = sink.write_all(data.as_bytes());
+            // Drop closes the pipe so the child's read sees EOF.
+        }
+    }
+
     let start = Instant::now();
     let status = loop {
         match child.try_wait() {
@@ -176,4 +221,58 @@ mod tests {
         // Leap day 2024-02-29 12:00:00 UTC
         assert_eq!(fmt_epoch(1_709_208_000), "2024-02-29 12:00:00");
     }
+
+    #[test]
+    fn fmt_epoch_year_2000_century_divisible_by_400_leap() {
+        // 2000-01-01 00:00:00 UTC — divisible by 400, so it IS a leap year.
+        assert_eq!(fmt_epoch(946_684_800), "2000-01-01 00:00:00");
+    }
+
+    #[test]
+    fn fmt_epoch_end_of_year_boundary() {
+        // 2023-12-31 23:59:59 UTC
+        assert_eq!(fmt_epoch(1_704_067_199), "2023-12-31 23:59:59");
+    }
+
+    #[test]
+    fn fmt_epoch_negative_before_unix_epoch() {
+        // 1969-12-31 23:59:59 UTC
+        assert_eq!(fmt_epoch(-1), "1969-12-31 23:59:59");
+        // 1969-12-31 00:00:00 UTC
+        assert_eq!(fmt_epoch(-86_400), "1969-12-31 00:00:00");
+    }
+
+    #[test]
+    fn fmt_epoch_february_non_leap_year_boundary() {
+        // 2023-02-28 00:00:00 UTC (2023 is not a leap year)
+        assert_eq!(fmt_epoch(1_677_542_400), "2023-02-28 00:00:00");
+        // 2023-03-01 00:00:00 UTC — next day after Feb 28 in non-leap year
+        assert_eq!(fmt_epoch(1_677_628_800), "2023-03-01 00:00:00");
+    }
+
+    #[test]
+    fn fmt_epoch_century_non_leap_year_1900_equivalent() {
+        // 1900 is NOT a leap year (div by 100 but not 400).
+        // 1900-03-01 00:00:00 UTC: days from epoch = (1900-1970)*365.25 ≈ use known anchor.
+        // 2100-02-28 00:00:00 UTC = epoch 4107456000; next day is Mar 1 (not Feb 29).
+        // We verify via the leap day boundary: 2100-02-28 + 86400 must be 2100-03-01.
+        assert_eq!(fmt_epoch(4_107_456_000), "2100-02-28 00:00:00");
+        assert_eq!(fmt_epoch(4_107_456_000 + 86_400), "2100-03-01 00:00:00");
+    }
+
+    #[test]
+    fn fmt_epoch_midnight_vs_end_of_day() {
+        // 2022-06-15 00:00:00 UTC
+        assert_eq!(fmt_epoch(1_655_251_200), "2022-06-15 00:00:00");
+        // 2022-06-15 23:59:59 UTC
+        assert_eq!(fmt_epoch(1_655_337_599), "2022-06-15 23:59:59");
+    }
+
+    #[test]
+    fn fmt_epoch_time_of_day_components() {
+        // 1970-01-01 01:02:03 UTC
+        assert_eq!(fmt_epoch(3723), "1970-01-01 01:02:03");
+        // 1970-01-01 23:59:59 UTC
+        assert_eq!(fmt_epoch(86_399), "1970-01-01 23:59:59");
+    }
 }

src/watch.rs

@@ -4,6 +4,7 @@ use std::sync::mpsc::{self, Receiver};
 use std::thread;
 use std::time::{Duration, Instant};
 
+use crate::backend::{Backend, System};
 use crate::config::Config;
 use crate::flow;
 use crate::notify::{log, notify, Urgency};
@@ -15,32 +16,34 @@ use crate::tailscale::TsHealth;
 enum Health {
     Up,
     DownNoNet,
+    /// Associated, but a captive portal is intercepting traffic (manual login).
+    CaptivePortal,
     DownTailscaleManual,
     DownTailscaleOther,
     NoAdapter,
 }
 
-fn classify(cfg: &Config, profile: &str) -> (Health, Option<String>) {
+fn classify(be: &dyn Backend, cfg: &Config, profile: &str) -> (Health, status::Status) {
-    let s = status::gather(cfg, profile);
+    let s = status::gather(be, cfg, profile);
-    if s.iface.is_none() {
+    let health = if s.iface.is_none() {
-        return (Health::NoAdapter, None);
+        Health::NoAdapter
-    }
+    } else if s.portal.is_some() {
-    let ssid = s.ssid.clone();
+        Health::CaptivePortal
-    if !s.internet {
+    } else if !s.internet {
-        return (Health::DownNoNet, ssid);
+        Health::DownNoNet
-    }
+    } else if s.tailscale_required {
-    if s.tailscale_required {
         match s.tailscale {
-            Some(TsHealth::Ok) => (Health::Up, ssid),
+            Some(TsHealth::Ok) => Health::Up,
             Some(TsHealth::NeedsLogin) | Some(TsHealth::NotInstalled) => {
-                (Health::DownTailscaleManual, ssid)
+                Health::DownTailscaleManual
             }
-            Some(_) => (Health::DownTailscaleOther, ssid),
+            Some(_) => Health::DownTailscaleOther,
-            None => (Health::DownTailscaleManual, ssid),
+            None => Health::DownTailscaleManual,
         }
     } else {
-        (Health::Up, ssid)
+        Health::Up
-    }
+    };
+    (health, s)
 }
 
 /// Tail `nmcli monitor` and ping the channel on link-state churn so we react
@@ -105,17 +108,18 @@ pub fn run(mut cfg: Config, run_initial: bool) -> i32 {
     let (tx, rx) = mpsc::channel::<()>();
     spawn_nm_monitor(tx);
 
+    let be = System;
     let mut profile = State::load(&cfg.settings.default_profile).profile;
     if run_initial {
         // Don't churn an already-working connection on (re)start.
-        let (h, _) = classify(&cfg, &profile);
+        let (h, _) = classify(&be, &cfg, &profile);
         if h == Health::Up {
             log(&format!(
                 "watch: already healthy on start (profile={profile}); skipping initial flow"
             ));
         } else {
             log(&format!("watch: initial flow for profile={profile}"));
-            let _ = flow::run(&cfg, &profile);
+            let _ = flow::run(&be, &cfg, &profile);
         }
     }
 
@@ -147,7 +151,8 @@ pub fn run(mut cfg: Config, run_initial: bool) -> i32 {
             last_flow_at = None; // allow immediate recovery on profile change
         }
 
-        let (health, ssid) = classify(&cfg, &profile);
+        let (health, s) = classify(&be, &cfg, &profile);
+        let ssid = s.ssid.clone();
         let transition = prev_health.as_ref() != Some(&health);
 
         match &health {
@@ -164,6 +169,18 @@ pub fn run(mut cfg: Config, run_initial: bool) -> i32 {
                 }
                 fail_streak = 0;
             }
+            Health::CaptivePortal => {
+                // Associated but gated behind a sign-in page we can't automate;
+                // notify once and don't hammer flow (reconnecting won't help).
+                if transition {
+                    let body = match s.portal.as_deref().filter(|u| !u.is_empty()) {
+                        Some(url) => format!("Sign in to continue: {url}"),
+                        None => format!("Sign in to continue ({profile})."),
+                    };
+                    notify("breadcrumbs: captive portal", &body, Urgency::Normal);
+                }
+                fail_streak = 0;
+            }
             Health::NoAdapter => {
                 if transition {
                     notify(
@@ -186,7 +203,8 @@ pub fn run(mut cfg: Config, run_initial: bool) -> i32 {
                 }
                 // Re-run flow only on transition so we land on the bootstrap net.
                 if transition || profile_changed {
-                    let _ = flow::run(&cfg, &profile);
+                    let _ = flow::run(&be, &cfg, &profile);
+                    last_flow_at = Some(Instant::now());
                 }
                 fail_streak = fail_streak.saturating_add(1);
             }
@@ -206,7 +224,7 @@ pub fn run(mut cfg: Config, run_initial: bool) -> i32 {
                         "watch: down ({:?}) profile={profile} ssid={:?} — running flow",
                         health, ssid
                     ));
-                    let outcome = flow::run(&cfg, &profile);
+                    let outcome = flow::run(&be, &cfg, &profile);
                     log(&format!("watch: recovery outcome = {:?}", outcome));
                     last_flow_at = Some(Instant::now());
                     fail_streak = if outcome.ok() {

tests/cli.rs

@@ -142,3 +142,350 @@ fn unknown_profile_override_is_reported() {
     let o = sb.cmd(&["--profile", "nope", "init"]);
     assert!(!o.status.success());
 }
+
+#[test]
+fn profile_list_marks_active_profile() {
+    let sb = Sandbox::new();
+
+    // Default profile is "away".
+    let o = sb.cmd(&["profile", "list"]);
+    assert!(o.status.success());
+    let out = stdout(&o);
+    // The active profile line starts with "* ".
+    assert!(
+        out.lines().any(|l| l.starts_with("* away")),
+        "active profile marker missing: {out}"
+    );
+    // Inactive profiles start with "  ".
+    assert!(
+        out.lines().any(|l| l.starts_with("  home")),
+        "inactive profile format wrong: {out}"
+    );
+
+    // After switching to "work" the marker should move.
+    sb.cmd(&["profile", "set", "work", "--no-apply"]);
+    let o = sb.cmd(&["profile", "list"]);
+    let out = stdout(&o);
+    assert!(out.lines().any(|l| l.starts_with("* work")));
+    assert!(out.lines().any(|l| l.starts_with("  away")));
+}
+
+#[test]
+fn add_saves_network_to_config() {
+    let sb = Sandbox::new();
+
+    let o = sb.cmd(&["add", "CafeWifi", "mypassword"]);
+    assert!(
+        o.status.success(),
+        "stderr: {}",
+        String::from_utf8_lossy(&o.stderr)
+    );
+    assert!(stdout(&o).contains("saved"));
+
+    // The network should now appear in the config file.
+    let text = fs::read_to_string(sb.config_file()).unwrap();
+    assert!(text.contains("CafeWifi"), "SSID missing from config");
+    assert!(text.contains("mypassword"), "password missing from config");
+}
+
+#[test]
+fn add_attaches_ssid_to_profile_at_position() {
+    let sb = Sandbox::new();
+
+    // First add without attaching, then add again with --to.
+    sb.cmd(&["add", "HomeWifi", "pw1"]);
+    let o = sb.cmd(&["add", "HomeWifi", "pw1", "--to", "home"]);
+    assert!(
+        o.status.success(),
+        "stderr: {}",
+        String::from_utf8_lossy(&o.stderr)
+    );
+
+    let text = fs::read_to_string(sb.config_file()).unwrap();
+    // After attaching, the home profile's networks list should contain HomeWifi.
+    assert!(
+        text.contains("HomeWifi"),
+        "SSID not found in config after --to: {text}"
+    );
+}
+
+#[test]
+fn add_to_unknown_profile_fails() {
+    let sb = Sandbox::new();
+    let o = sb.cmd(&["add", "SomeNet", "pw", "--to", "nonexistent"]);
+    assert!(!o.status.success());
+}
+
+#[test]
+fn add_updates_existing_network_password() {
+    let sb = Sandbox::new();
+
+    sb.cmd(&["add", "MyNet", "oldpass"]);
+    let o = sb.cmd(&["add", "MyNet", "newpass"]);
+    assert!(o.status.success());
+
+    let text = fs::read_to_string(sb.config_file()).unwrap();
+    assert!(text.contains("newpass"), "updated password missing");
+    // Old password must be gone.
+    assert!(!text.contains("oldpass"), "old password still present");
+    // Only one entry for MyNet.
+    assert_eq!(
+        text.matches("MyNet").count(),
+        1,
+        "duplicate network entries"
+    );
+}
+
+#[test]
+fn forget_removes_network_from_config() {
+    let sb = Sandbox::new();
+
+    sb.cmd(&["add", "ToDelete", "pw"]);
+    let text = fs::read_to_string(sb.config_file()).unwrap();
+    assert!(text.contains("ToDelete"));
+
+    let o = sb.cmd(&["forget", "ToDelete"]);
+    assert!(o.status.success());
+    assert!(stdout(&o).contains("forgot"));
+
+    let text = fs::read_to_string(sb.config_file()).unwrap();
+    assert!(
+        !text.contains("ToDelete"),
+        "network still in config after forget"
+    );
+}
+
+#[test]
+fn forget_nonexistent_network_is_graceful() {
+    let sb = Sandbox::new();
+    // Should succeed (idempotent) even if the SSID was never saved.
+    let o = sb.cmd(&["forget", "NeverSaved"]);
+    assert!(o.status.success());
+}
+
+#[test]
+fn forget_removes_ssid_from_profile_networks_list() {
+    let sb = Sandbox::new();
+
+    // Add "WorkNet" and attach it to the "work" profile.
+    sb.cmd(&["add", "WorkNet", "pw", "--to", "work"]);
+    let text = fs::read_to_string(sb.config_file()).unwrap();
+    assert!(text.contains("WorkNet"));
+
+    sb.cmd(&["forget", "WorkNet"]);
+
+    let text = fs::read_to_string(sb.config_file()).unwrap();
+    assert!(
+        !text.contains("WorkNet"),
+        "SSID still in profile after forget"
+    );
+}
+
+#[test]
+fn list_masks_passwords_by_default() {
+    let sb = Sandbox::new();
+    sb.cmd(&["add", "SecretNet", "hunter2"]);
+
+    let o = sb.cmd(&["list"]);
+    assert!(o.status.success());
+    let out = stdout(&o);
+    assert!(
+        !out.contains("hunter2"),
+        "plain-text password exposed in list"
+    );
+    // A masking bullet should appear.
+    assert!(out.contains('•'), "no masking character in list output");
+}
+
+#[test]
+fn list_masks_multibyte_password_without_panicking() {
+    let sb = Sandbox::new();
+    // A password whose first character is multi-byte UTF-8 used to panic the
+    // byte-slicing mask(); list must mask it cleanly instead.
+    sb.cmd(&["add", "UnicodeNet", "ñoño-café-🔐"]);
+
+    let o = sb.cmd(&["list"]);
+    assert!(
+        o.status.success(),
+        "list crashed on multibyte password: {}",
+        String::from_utf8_lossy(&o.stderr)
+    );
+    let out = stdout(&o);
+    assert!(
+        !out.contains("ñoño-café-🔐"),
+        "password leaked in masked list"
+    );
+    assert!(out.contains('•'), "no masking character in list output");
+}
+
+#[test]
+fn list_show_passwords_reveals_password() {
+    let sb = Sandbox::new();
+    sb.cmd(&["add", "SecretNet", "hunter2"]);
+
+    let o = sb.cmd(&["list", "--show-passwords"]);
+    assert!(o.status.success());
+    assert!(
+        stdout(&o).contains("hunter2"),
+        "password not shown with --show-passwords"
+    );
+}
+
+#[test]
+fn cd_prints_config_directory() {
+    let sb = Sandbox::new();
+    // Trigger config creation first.
+    sb.cmd(&["list"]);
+
+    let o = sb.cmd(&["cd"]);
+    assert!(o.status.success());
+    let out = stdout(&o).trim().to_string();
+    assert!(!out.is_empty(), "cd produced no output");
+    // The printed path must end with "breadcrumbs" (the config subdirectory).
+    assert!(out.ends_with("breadcrumbs"), "unexpected config dir: {out}");
+}
+
+#[test]
+fn doctor_runs_without_crashing() {
+    let sb = Sandbox::new();
+    // With an empty PATH, nmcli/tailscale are absent. Doctor should report
+    // "MISSING"/"absent" but still exit successfully (it's a diag tool).
+    let o = sb.cmd(&["doctor"]);
+    assert!(
+        o.status.success(),
+        "stderr: {}",
+        String::from_utf8_lossy(&o.stderr)
+    );
+    let out = stdout(&o);
+    assert!(out.contains("nmcli"), "doctor missing nmcli line");
+    assert!(out.contains("tailscale"), "doctor missing tailscale line");
+}
+
+#[test]
+fn status_exits_nonzero_when_unhealthy() {
+    let sb = Sandbox::new();
+    // No nmcli/tailscale → internet check fails → unhealthy → exit code 1.
+    let o = sb.cmd(&["status"]);
+    assert!(
+        !o.status.success(),
+        "expected non-zero exit for unhealthy status"
+    );
+    let out = stdout(&o);
+    assert!(
+        out.contains("breadcrumbs"),
+        "missing header in status output"
+    );
+    assert!(
+        out.contains("profile"),
+        "missing profile line in status output"
+    );
+}
+
+#[test]
+fn profile_override_flag_does_not_persist() {
+    let sb = Sandbox::new();
+
+    // Set profile to "home" persistently.
+    sb.cmd(&["profile", "set", "home", "--no-apply"]);
+
+    // Use --profile flag to override for a single run (status).
+    let o = sb.cmd(&["--profile", "work", "status"]);
+    // Status exits non-zero (no network), but it should show the overridden profile.
+    let out = stdout(&o);
+    assert!(out.contains("work"), "override profile not shown in status");
+
+    // The persistent profile must still be "home".
+    let o = sb.cmd(&["profile", "get"]);
+    assert_eq!(stdout(&o).trim(), "home");
+}
+
+#[test]
+fn add_hidden_flag_is_persisted() {
+    let sb = Sandbox::new();
+    let o = sb.cmd(&["add", "HiddenNet", "pw", "--hidden"]);
+    assert!(o.status.success());
+
+    let text = fs::read_to_string(sb.config_file()).unwrap();
+    assert!(text.contains("hidden = true"), "hidden flag not persisted");
+}
+
+#[test]
+fn status_json_is_valid_and_machine_readable() {
+    let sb = Sandbox::new();
+    // No nmcli/tailscale → unhealthy, exit 1, but JSON must still be valid.
+    let o = sb.cmd(&["status", "--json"]);
+    assert!(
+        !o.status.success(),
+        "expected non-zero exit for unhealthy status"
+    );
+    let v: serde_json::Value =
+        serde_json::from_str(&stdout(&o)).expect("status --json did not emit valid JSON");
+    assert_eq!(v["profile"], "away");
+    assert_eq!(v["internet"], false);
+    assert_eq!(v["healthy"], false);
+    assert!(v["tailscale"].is_object());
+}
+
+#[test]
+fn profile_add_persists_detect_ssids_and_remove_deletes() {
+    let sb = Sandbox::new();
+
+    let o = sb.cmd(&[
+        "profile", "add", "lab", "--detect", "LabWifi", "--detect", "LabGuest",
+    ]);
+    assert!(
+        o.status.success(),
+        "stderr: {}",
+        String::from_utf8_lossy(&o.stderr)
+    );
+
+    let text = fs::read_to_string(sb.config_file()).unwrap();
+    assert!(
+        text.contains("[profiles.lab]"),
+        "profile not written: {text}"
+    );
+    assert!(
+        text.contains("LabWifi") && text.contains("LabGuest"),
+        "detect ssids missing"
+    );
+
+    // Adding the same profile again is rejected.
+    assert!(!sb.cmd(&["profile", "add", "lab"]).status.success());
+
+    // Remove it.
+    let o = sb.cmd(&["profile", "remove", "lab"]);
+    assert!(o.status.success());
+    let text = fs::read_to_string(sb.config_file()).unwrap();
+    assert!(
+        !text.contains("[profiles.lab]"),
+        "profile still present after remove"
+    );
+}
+
+#[test]
+fn profile_remove_core_is_rejected() {
+    let sb = Sandbox::new();
+    let o = sb.cmd(&["profile", "remove", "home"]);
+    assert!(!o.status.success(), "removing a core profile should fail");
+}
+
+#[test]
+fn install_service_writes_unit_file() {
+    let sb = Sandbox::new();
+    // Install but don't enable (systemctl is absent in the empty PATH, but
+    // writing the unit file should succeed regardless).
+    let o = sb.cmd(&["install-service", "--no-enable"]);
+    assert!(
+        o.status.success(),
+        "stderr: {}",
+        String::from_utf8_lossy(&o.stderr)
+    );
+    let unit = sb.root.join(".config/systemd/user/breadcrumbs.service");
+    assert!(unit.exists(), "unit file not written at {}", unit.display());
+    let content = fs::read_to_string(&unit).unwrap();
+    assert!(content.contains("ExecStart="), "unit missing ExecStart");
+    assert!(
+        content.contains("breadcrumbs watch"),
+        "unit missing watch subcommand"
+    );
+}