Add bread init: Hyprland compositor layer-rule integration

Installs the layerrule blur/ignore_alpha/animation integration that
breadbar's translucency depends on into a user's hyprland.lua, with a
consent-gated single marked block, timestamped backup, dry-run/--yes,
and --undo. Generates a self-contained ~/.config/hypr/bread.lua that
reads layerrules.json (bread-theme layerrules) and emits hl.layer_rule
calls, appearance fields only. Falls back to printing a snippet
(translated to hyprlang .conf syntax when relevant) rather than
writing when the config isn't a Lua hyprland.lua bread recognizes, and
refuses to install when an existing breadbar layer rule (e.g. BOS's
own dotfiles) is already found under ~/.config/hypr.

bread doctor now reports compositor integration status via a pure
filesystem check, independent of the daemon; it never installs
anything itself.

Wired as a top-level Commands::Init (not a HooksCommand variant) since
it needs diff/consent/backup/undo machinery the hooks family has no
use for.

bread-cli/src/main.rs

@@ -1,3 +1,4 @@
+mod init;
 mod hooks_git;
 mod hooks_shell;
 mod modules_mgmt;
@@ -99,6 +100,22 @@ enum Commands {
         #[arg(long)]
         json: bool,
     },
+    /// Install bread's Hyprland compositor layer-rule integration
+    /// (breadbar/breadbox blur, ignore_alpha, animation) into
+    /// ~/.config/hypr/hyprland.lua, with consent, a backup, and full undo.
+    /// See bread-cli/src/init.rs for the design rationale.
+    Init {
+        /// Print the proposed diff and change nothing
+        #[arg(long)]
+        dry_run: bool,
+        /// Skip the confirmation prompt (for scripted/image builds)
+        #[arg(long)]
+        yes: bool,
+        /// Remove the previously installed marked block instead of
+        /// installing it
+        #[arg(long)]
+        undo: bool,
+    },
 }
 
 #[derive(Subcommand, Debug)]
@@ -224,6 +241,9 @@ async fn main() -> Result<()> {
                 print_doctor(&socket).await?;
             }
         }
+        Commands::Init { dry_run, yes, undo } => {
+            init::run(dry_run, yes, undo)?;
+        }
     }
 
     Ok(())
@@ -691,6 +711,7 @@ async fn print_doctor(socket: &Path) -> Result<()> {
         println!();
         println!("  start the daemon:   systemctl --user start breadd");
         println!("  view logs:          journalctl --user -u breadd -f");
+        print_compositor_doctor_section();
         return Ok(());
     }
 
@@ -775,6 +796,20 @@ fn render_doctor(health: &Value) {
             }
         }
     }
+
+    print_compositor_doctor_section();
+}
+
+/// Compositor integration status — pure filesystem check, independent of
+/// the daemon, so it prints the same whether breadd is up or not. Reports
+/// only; `bread doctor` never installs anything (that's `bread init`'s
+/// job).
+fn print_compositor_doctor_section() {
+    println!();
+    println!("compositor");
+    for line in init::doctor_report(&init::hypr_dir()) {
+        println!("{line}");
+    }
 }
 
 fn config_directory() -> PathBuf {