feat(frontend): show transcription + keyword search + channel/date filters + speaker leaderboard

- cards now render transcription snippet (expandable); no-transcript placeholder
- toolbar: search box (transcription+username ILIKE), speaker filter (existing),
  channel filter, start/end date range, RESET
- new DECK/LEADERBOARD tabs: leaderboard = per-speaker clips, est duration,
  transcribed words (useRecordingsSummary → recordings.summary); click a row
  jumps the deck to that speaker's clips
- hooks: filter-driven SWR cache key (fields serialized), representative key
  matcher for delete/WS-sync across all filter views; useRecordingsSummary hook
- recordingsApi.list generalized to RecordingListParams (q/startDate/endDate)

services/frontend/src/lib/api/recordings.ts

@@ -1,20 +1,34 @@
 import { orpc } from "@/lib/orpc/client";
-import type { PaginatedRecordings } from "@/lib/types";
+import type { PaginatedRecordings, SpeakerSummary } from "@/lib/types";
+
+export interface RecordingListParams {
+  limit?: number;
+  channelId?: string;
+  userId?: string;
+  cursor?: string;
+  /** keyword search against transcription + username */
+  q?: string;
+  /** created_at lower bound (epoch ms) */
+  startDate?: number;
+  /** created_at upper bound (epoch ms) */
+  endDate?: number;
+}
 
 export const recordingsApi = {
-  list: (
-    limit?: number,
-    channelId?: string,
-    userId?: string,
-    cursor?: string,
-  ) =>
+  list: (params: RecordingListParams = {}) =>
     orpc.recordings.list({
-      limit,
-      channelId,
-      userId,
-      cursor,
+      limit: params.limit,
+      channelId: params.channelId,
+      userId: params.userId,
+      cursor: params.cursor,
+      q: params.q,
+      startDate: params.startDate,
+      endDate: params.endDate,
     }) as unknown as Promise<PaginatedRecordings>,
 
   delete: (id: string) =>
     orpc.recordings.delete({ id }) as unknown as Promise<{ ok: boolean }>,
+
+  summary: () =>
+    orpc.recordings.summary({}) as unknown as Promise<SpeakerSummary[]>,
 };

services/frontend/src/lib/types/recording.ts

@@ -13,6 +13,7 @@ export interface VoiceRecording {
   upload_error?: string | null;
   created_at: number;
   uploaded_at?: number | null;
+  transcription?: string | null;
 }
 
 export interface PaginatedRecordings {
@@ -20,3 +21,15 @@ export interface PaginatedRecordings {
   nextCursor: string | null;
   hasMore: boolean;
 }
+
+/** recordings.summary — per-speaker leaderboard. */
+export interface SpeakerSummary {
+  user_id: string;
+  username: string;
+  avatar_url: string | null;
+  clips: number;
+  est_duration_s: number;
+  words: number;
+  transcribed: number;
+  last_at: number;
+}