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/stores/app-store.ts

@@ -1,7 +1,8 @@
 import { create } from "zustand";
-import type { AppSettings } from "@/types/settings";
+import type { AppSettings, BoardSortOrder } from "@/types/settings";
 import type { BoardMeta, ColumnWidth } from "@/types/board";
-import { loadSettings, saveSettings, listBoards, ensureDataDirs } from "@/lib/storage";
+import { loadSettings, saveSettings, listBoards, ensureDataDirs, loadBoard } from "@/lib/storage";
+import { isPermissionGranted, requestPermission, sendNotification } from "@tauri-apps/plugin-notification";
 
 export type View = { type: "board-list" } | { type: "board"; boardId: string };
 
@@ -20,6 +21,9 @@ interface AppState {
   setView: (view: View) => void;
   refreshBoards: () => Promise<void>;
   addRecentBoard: (boardId: string) => void;
+  setBoardSortOrder: (order: BoardSortOrder) => void;
+  setBoardManualOrder: (ids: string[]) => void;
+  getSortedBoards: () => BoardMeta[];
 }
 
 function applyTheme(theme: AppSettings["theme"]): void {
@@ -63,6 +67,9 @@ export const useAppStore = create<AppState>((set, get) => ({
     density: "comfortable",
     defaultColumnWidth: "standard",
     windowState: null,
+    boardSortOrder: "updated",
+    boardManualOrder: [],
+    lastNotificationCheck: null,
   },
   boards: [],
   view: { type: "board-list" },
@@ -75,6 +82,45 @@ export const useAppStore = create<AppState>((set, get) => ({
     set({ settings, boards, initialized: true });
     applyTheme(settings.theme);
     applyAppearance(settings);
+
+    // Due date notifications (once per hour)
+    const lastCheck = settings.lastNotificationCheck;
+    const hourAgo = new Date(Date.now() - 60 * 60 * 1000).toISOString();
+    if (!lastCheck || lastCheck < hourAgo) {
+      try {
+        let granted = await isPermissionGranted();
+        if (!granted) {
+          const perm = await requestPermission();
+          granted = perm === "granted";
+        }
+        if (granted) {
+          let dueToday = 0;
+          let overdue = 0;
+          const today = new Date();
+          const todayStr = today.toDateString();
+
+          for (const meta of boards) {
+            try {
+              const board = await loadBoard(meta.id);
+              for (const card of Object.values(board.cards)) {
+                if (!card.dueDate) continue;
+                const due = new Date(card.dueDate);
+                if (due.toDateString() === todayStr) dueToday++;
+                else if (due < today) overdue++;
+              }
+            } catch { /* skip */ }
+          }
+
+          if (dueToday > 0) {
+            sendNotification({ title: "OpenPylon", body: `You have ${dueToday} card${dueToday > 1 ? "s" : ""} due today` });
+          }
+          if (overdue > 0) {
+            sendNotification({ title: "OpenPylon", body: `You have ${overdue} overdue card${overdue > 1 ? "s" : ""}` });
+          }
+        }
+        updateAndSave(get, set, { lastNotificationCheck: new Date().toISOString() });
+      } catch { /* notification plugin not available */ }
+    }
   },
 
   setTheme: (theme) => {
@@ -117,4 +163,44 @@ export const useAppStore = create<AppState>((set, get) => ({
     ].slice(0, 10);
     updateAndSave(get, set, { recentBoardIds: recent });
   },
+
+  setBoardSortOrder: (boardSortOrder) => {
+    // When switching to manual for the first time, snapshot current order
+    if (boardSortOrder === "manual" && get().settings.boardManualOrder.length === 0) {
+      const currentSorted = get().getSortedBoards();
+      updateAndSave(get, set, {
+        boardSortOrder,
+        boardManualOrder: currentSorted.map((b) => b.id),
+      });
+    } else {
+      updateAndSave(get, set, { boardSortOrder });
+    }
+  },
+
+  setBoardManualOrder: (boardManualOrder) => {
+    updateAndSave(get, set, { boardManualOrder });
+  },
+
+  getSortedBoards: () => {
+    const { boards, settings } = get();
+    const order = settings.boardSortOrder;
+
+    if (order === "manual") {
+      const manualOrder = settings.boardManualOrder;
+      const orderMap = new Map(manualOrder.map((id, i) => [id, i]));
+      return [...boards].sort((a, b) => {
+        const ai = orderMap.get(a.id) ?? Infinity;
+        const bi = orderMap.get(b.id) ?? Infinity;
+        return ai - bi;
+      });
+    }
+    if (order === "title") {
+      return [...boards].sort((a, b) => a.title.localeCompare(b.title));
+    }
+    if (order === "created") {
+      return [...boards].sort((a, b) => b.createdAt.localeCompare(a.createdAt));
+    }
+    // "updated" — default, already sorted from listBoards
+    return boards;
+  },
 }));