feat: Phase 3 Desktop — native menu, auto-update, hidden terminal

- #![windows_subsystem = "windows"]: no console window on Windows release builds
- CREATE_NO_WINDOW (0x08000000): Python backend subprocess hidden on Windows
- Native menu bar: Fichier (N/Fermer/Quitter) + Edition (Undo/Redo/Cut/Copy/Paste/SelectAll) + Aide (About)
- Auto-update: tauri-plugin-updater checks Gitea releases endpoint
- tauri.conf.json: updater plugin config with passive install mode
- ROADMAP: Phase 3 marked as complete (11/11 subtasks done)

desktop/src/main.rs

@@ -1,3 +1,10 @@
+//! ObsiGate Desktop — Native Tauri shell for ObsiGate web app.
+//!
+//! Spawns a Python FastAPI backend, then opens the frontend in a
+//! native webview. No terminal window on Windows (subsystem = "windows").
+
+#![cfg_attr(not(debug_assertions), windows_subsystem = "windows")]
+
 use log::{error, info, warn};
 use serde::{Deserialize, Serialize};
 use std::fs::{self, OpenOptions};
@@ -495,6 +502,7 @@ fn main() {
         .plugin(tauri_plugin_fs::init())
         .plugin(tauri_plugin_process::init())
         .plugin(tauri_plugin_store::Builder::default().build())
+        .plugin(tauri_plugin_updater::Builder::new().build())
         .plugin(tauri_plugin_single_instance::init(|app, _args, _cwd| {
             // Focus existing window when second instance launched
             if let Some(window) = app.get_webview_window("main") {
@@ -522,6 +530,9 @@ fn main() {
             list_dirs,
         ])
         .setup(move |app| {
+            // Build native menu bar (File / Edit / Help)
+            let _ = build_native_menu(app);
+
             // Restore window position/size
             if let Some(window) = app.get_webview_window("main") {
                 if let (Some(x), Some(y)) = (config.window_x, config.window_y) {
@@ -635,6 +646,106 @@ fn main() {
     });
 }
 
+// ── Native Menu Bar ──────────────────────────────────────────────────────────
+
+fn build_native_menu(app: &tauri::App) -> Result<(), Box<dyn std::error::Error>> {
+    use tauri::menu::{
+        MenuBuilder, MenuItemBuilder, SubmenuBuilder, PredefinedMenuItem,
+    };
+
+    // File menu
+    let new_window = MenuItemBuilder::with_id("file_new_window", "Nouvelle fenêtre")
+        .accelerator("CmdOrCtrl+N")
+        .build(app)?;
+    let close_window = MenuItemBuilder::with_id("file_close", "Fermer")
+        .accelerator("CmdOrCtrl+W")
+        .build(app)?;
+    let file_sep = PredefinedMenuItem::separator(app)?;
+    let quit = MenuItemBuilder::with_id("file_quit", "Quitter")
+        .accelerator("CmdOrCtrl+Q")
+        .build(app)?;
+    let file_menu = SubmenuBuilder::new(app, "Fichier")
+        .item(&new_window)
+        .item(&close_window)
+        .item(&file_sep)
+        .item(&quit)
+        .build()?;
+
+    // Edit menu
+    let undo = MenuItemBuilder::with_id("edit_undo", "Annuler")
+        .accelerator("CmdOrCtrl+Z")
+        .build(app)?;
+    let redo = MenuItemBuilder::with_id("edit_redo", "Rétablir")
+        .accelerator("CmdOrCtrl+Shift+Z")
+        .build(app)?;
+    let edit_sep = PredefinedMenuItem::separator(app)?;
+    let cut = MenuItemBuilder::with_id("edit_cut", "Couper")
+        .accelerator("CmdOrCtrl+X")
+        .build(app)?;
+    let copy = MenuItemBuilder::with_id("edit_copy", "Copier")
+        .accelerator("CmdOrCtrl+C")
+        .build(app)?;
+    let paste = MenuItemBuilder::with_id("edit_paste", "Coller")
+        .accelerator("CmdOrCtrl+V")
+        .build(app)?;
+    let select_all = MenuItemBuilder::with_id("edit_select_all", "Tout sélectionner")
+        .accelerator("CmdOrCtrl+A")
+        .build(app)?;
+    let edit_menu = SubmenuBuilder::new(app, "Édition")
+        .item(&undo)
+        .item(&redo)
+        .item(&edit_sep)
+        .item(&cut)
+        .item(&copy)
+        .item(&paste)
+        .item(&edit_sep.clone())
+        .item(&select_all)
+        .build()?;
+
+    // Help menu
+    let about = MenuItemBuilder::with_id("help_about", "À propos d'ObsiGate")
+        .build(app)?;
+    let help_menu = SubmenuBuilder::new(app, "Aide")
+        .item(&about)
+        .build()?;
+
+    let menu = MenuBuilder::new(app)
+        .item(&file_menu)
+        .item(&edit_menu)
+        .item(&help_menu)
+        .build()?;
+
+    app.set_menu(menu)?;
+
+    // Handle menu events
+    app.on_menu_event(move |app, event| {
+        match event.id().as_ref() {
+            "file_quit" => {
+                info!("Quit from menu");
+                app.exit(0);
+            }
+            "file_close" => {
+                if let Some(window) = app.get_webview_window("main") {
+                    let _ = window.close();
+                }
+            }
+            "help_about" => {
+                if let Some(window) = app.get_webview_window("main") {
+                    let _ = window.eval(
+                        r#"alert('ObsiGate Desktop v2.0.0\n\nPorte d\'entrée native pour vos vaults Obsidian.\nConstruit avec Tauri + Rust.\n\n© Bruno Charest — Licence MIT\nhttps://git.dracodev.net/Projets/ObsiGate')"#
+                    );
+                }
+            }
+            "edit_undo" | "edit_redo" | "edit_cut" | "edit_copy" | "edit_paste" | "edit_select_all" => {
+                // Let the webview handle these natively
+            }
+            _ => {}
+        }
+    });
+
+    Ok(())
+}
+
 // ── Tray Menu ───────────────────────────────────────────────────────────────
 
 fn build_tray_menu(app: &tauri::App) -> Result<(), Box<dyn std::error::Error>> {