refactor(v032): 탭 ARIA canonical + loadExpired dead-code 제거 (#14, #18)

- App.tsx 탭 button 의 aria-pressed → role="tab" + aria-selected
  (canonical pattern, a11y audit 정정)
- store.ts loadExpired action + test 제거 (App.tsx 호출 0건,
  loadInitial/refreshMeta 가 inline fetch — dead code)

src/renderer/inbox/App.tsx

@@ -106,8 +106,10 @@ export function App(): React.ReactElement {
           ).map((t) => (
             <button
               key={t.key}
+              type="button"
+              role="tab"
+              aria-selected={view === t.key}
               onClick={() => setView(t.key)}
-              aria-pressed={view === t.key}
               style={tabBtnStyle(view === t.key)}
             >
               {t.label}({t.count})

src/renderer/inbox/store.ts

@@ -58,7 +58,6 @@ interface InboxState {
   restoreNote: (id: string) => Promise<void>;
   permanentDeleteNote: (id: string) => Promise<void>;
   emptyTrash: () => Promise<void>;
-  loadExpired: () => Promise<void>;
   trashExpiredBatch: (ids: string[]) => Promise<void>;
   snoozeExpired: () => void;
   recheckOllama: () => Promise<void>;
@@ -235,10 +234,6 @@ export const useInbox = create<InboxState>((set, get) => ({
       set({ trashNotes: [], trashCount: 0 });
     }
   },
-  async loadExpired() {
-    const expiredCandidates = await inboxApi.listExpired();
-    set({ expiredCandidates });
-  },
   async trashExpiredBatch(ids: string[]) {
     const r = await inboxApi.trashExpiredBatch(ids);
     if (!r.confirmed) return;