Scaffold BOS repo: dotfiles, ISO profile, and bos-settings GTK4 app

Implements all four components from the BOS spec:
- dotfiles/: default Hyprland, bread, breadbox, breadcrumbs configs
- iso/: archiso profiledef, package list, Calamares YAML modules, post-install.sh
- bos-settings/: Cargo workspace with GTK4 settings app (8 views: snapshots,
  packages, bread, breadbar, breadbox, breadcrumbs, breadpad, hyprland)

https://claude.ai/code/session_01WszGHvCmxgcyTwNSkfLF9P

bos-settings/src/ui/views/breadpad.rs

@@ -0,0 +1,118 @@
+use gtk4::prelude::*;
+use gtk4::{Box as GBox, Button, Entry, Label, Orientation, Switch};
+use serde::{Deserialize, Serialize};
+use std::cell::RefCell;
+use std::rc::Rc;
+
+use crate::config;
+
+#[derive(Deserialize, Serialize, Clone)]
+pub struct BreadpadConfig {
+    #[serde(default = "default_model")]
+    pub model: String,
+    #[serde(default = "default_true")]
+    pub reminders: bool,
+    #[serde(default = "default_true")]
+    pub calendar: bool,
+}
+
+fn default_model() -> String {
+    "claude-sonnet-4-6".to_string()
+}
+
+fn default_true() -> bool {
+    true
+}
+
+impl Default for BreadpadConfig {
+    fn default() -> Self {
+        Self {
+            model: default_model(),
+            reminders: true,
+            calendar: true,
+        }
+    }
+}
+
+fn config_path() -> std::path::PathBuf {
+    config::config_dir().join("breadpad/breadpad.toml")
+}
+
+pub fn build() -> GBox {
+    let path = config_path();
+    let cfg: BreadpadConfig = config::load(&path).unwrap_or_default();
+    let cfg = Rc::new(RefCell::new(cfg));
+
+    let vbox = GBox::new(Orientation::Vertical, 12);
+    vbox.add_css_class("view-content");
+
+    let title = Label::new(Some("breadpad"));
+    title.add_css_class("title");
+    title.set_xalign(0.0);
+    vbox.append(&title);
+
+    // Model entry
+    let row = GBox::new(Orientation::Horizontal, 16);
+    let lbl = Label::new(Some("Model"));
+    lbl.set_hexpand(true);
+    lbl.set_xalign(0.0);
+    let model_entry = Entry::new();
+    model_entry.set_text(&cfg.borrow().model);
+    {
+        let cfg = cfg.clone();
+        model_entry.connect_changed(move |e| {
+            cfg.borrow_mut().model = e.text().to_string();
+        });
+    }
+    row.append(&lbl);
+    row.append(&model_entry);
+    vbox.append(&row);
+
+    // Reminders toggle
+    let row = GBox::new(Orientation::Horizontal, 16);
+    let lbl = Label::new(Some("Reminders"));
+    lbl.set_hexpand(true);
+    lbl.set_xalign(0.0);
+    let sw = Switch::new();
+    sw.set_active(cfg.borrow().reminders);
+    {
+        let cfg = cfg.clone();
+        sw.connect_active_notify(move |s| {
+            cfg.borrow_mut().reminders = s.is_active();
+        });
+    }
+    row.append(&lbl);
+    row.append(&sw);
+    vbox.append(&row);
+
+    // Calendar toggle
+    let row = GBox::new(Orientation::Horizontal, 16);
+    let lbl = Label::new(Some("Calendar integration"));
+    lbl.set_hexpand(true);
+    lbl.set_xalign(0.0);
+    let sw = Switch::new();
+    sw.set_active(cfg.borrow().calendar);
+    {
+        let cfg = cfg.clone();
+        sw.connect_active_notify(move |s| {
+            cfg.borrow_mut().calendar = s.is_active();
+        });
+    }
+    row.append(&lbl);
+    row.append(&sw);
+    vbox.append(&row);
+
+    let save_btn = Button::with_label("Save");
+    save_btn.set_margin_top(16);
+    save_btn.set_halign(gtk4::Align::Start);
+    {
+        let cfg = cfg.clone();
+        let path = path.clone();
+        save_btn.connect_clicked(move |_| {
+            let _ = config::save(&path, &*cfg.borrow());
+        });
+    }
+    vbox.append(&save_btn);
+
+    vbox
+}