feat: Phase 3 - filter bar, keyboard navigation, notifications, comments

- FilterBar component with text search, label chips, due date and priority dropdowns
- "/" keyboard shortcut and toolbar button to toggle filter bar
- Keyboard card navigation with J/K/H/L keys, Enter to open, Escape to clear
- Focus ring on keyboard-selected cards with auto-scroll
- Desktop notifications for due/overdue cards via tauri-plugin-notification
- CommentsSection component with add/delete and relative timestamps
- Filtered card count display in column headers

src-tauri/Cargo.toml

@@ -23,6 +23,7 @@ tauri-plugin-opener = "2"
 tauri-plugin-fs = "2"
 tauri-plugin-dialog = "2"
 tauri-plugin-shell = "2"
+tauri-plugin-notification = "2"
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
 

src-tauri/capabilities/default.json

@@ -17,9 +17,12 @@
     "dialog:default",
     "shell:default",
     "fs:default",
+    "fs:read-all",
+    "fs:write-all",
     "core:window:allow-set-size",
     "core:window:allow-set-position",
     "core:window:allow-outer-size",
-    "core:window:allow-outer-position"
+    "core:window:allow-outer-position",
+    "notification:default"
   ]
 }

src-tauri/src/lib.rs

@@ -17,6 +17,7 @@ pub fn run() {
         .plugin(tauri_plugin_fs::init())
         .plugin(tauri_plugin_dialog::init())
         .plugin(tauri_plugin_shell::init())
+        .plugin(tauri_plugin_notification::init())
         .setup(|app| {
             // Get portable data directory next to the exe
             let exe_path =