feat(bd-318): implement QueueView container with filtering and batch support

QueueView now supports:
- Filtering items via CommandPalette (Cmd+K)
- Hide snoozed items by default (showSnoozed prop)
- Show snooze count indicator when items are hidden
- Support batch mode entry for sections with 2+ items
- Filter by type prop for programmatic filtering

Added snoozedUntil field to FocusItem type and updated fixtures.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

tests/helpers/fixtures.ts

@@ -4,7 +4,7 @@
  * Centralized here to avoid duplication across test files.
  */
 
-import type { FocusItem } from "@/lib/types";
+import type { FocusItem, InboxItem } from "@/lib/types";
 
 /** Create a FocusItem with sensible defaults, overridable per field. */
 export function makeFocusItem(
@@ -20,6 +20,23 @@ export function makeFocusItem(
     updatedAt: new Date().toISOString(),
     contextQuote: null,
     requestedBy: null,
+    snoozedUntil: null,
+    ...overrides,
+  };
+}
+
+/** Create an InboxItem with sensible defaults, overridable per field. */
+export function makeInboxItem(
+  overrides: Partial<InboxItem> = {}
+): InboxItem {
+  return {
+    id: "inbox-item-1",
+    title: "You were mentioned in #312",
+    type: "mention",
+    triaged: false,
+    createdAt: new Date().toISOString(),
+    snippet: "@user can you look at this?",
+    actor: "alice",
     ...overrides,
   };
 }