Add phone playback reporting and pause sharing to the API

Phones that read system media sessions report playback themselves:
- POST /me/devices issues a per-phone token that can only call
  POST /devices/now-playing; revocable, hashed at rest, 10 per user
- Reports name the app ("via Spotify"); unknown apps use the OS label
- Push-reported playback expires after 9 minutes of silence, since
  phones send a heartbeat every 4 minutes while playing

Users can pause sharing (PUT /me/sharing: 1h, 8h, indefinitely). While
paused, connections aren't polled, phone reports are dropped, nothing is
added to history, and the current track switches to "played … ago".

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MzFywujuH9TiuXbr9vjoX8

apps/api/src/db/schema.ts

@@ -26,6 +26,8 @@ export const users = pgTable('users', {
   avatarUrl: varchar('avatar_url', { length: 500 }),
   preferredService: text('preferred_service').$type<StreamingService>(),
   /** Billing plan. Kept in sync by the billing webhook (RevenueCat/Stripe) — see lib/entitlements.ts */
+  /** While in the future, nothing new is shared: services aren't polled and phone reports are dropped. */
+  sharingPausedUntil: timestamp('sharing_paused_until', { withTimezone: true }),
   plan: text('plan').$type<Plan>().notNull().default('free'),
   planExpiresAt: timestamp('plan_expires_at', { withTimezone: true }),
   createdAt: createdAt(),
@@ -134,6 +136,8 @@ export const nowPlaying = pgTable(
       .notNull()
       .references(() => tracks.id),
     source: text('source').$type<NowPlayingProvider>().notNull(),
+    /** App name when a phone reported it, e.g. "Spotify". */
+    sourceApp: text('source_app'),
     isPlaying: boolean('is_playing').notNull(),
     progressMs: integer('progress_ms'),
     startedAt: timestamp('started_at', { withTimezone: true }).notNull().defaultNow(),
@@ -142,6 +146,24 @@ export const nowPlaying = pgTable(
   (t) => [index('now_playing_track_idx').on(t.trackId)],
 );
 
+/** Phones that report playback directly (Android media sessions). Each has its own revocable token. */
+export const devices = pgTable(
+  'devices',
+  {
+    id: uuid('id').primaryKey().defaultRandom(),
+    userId: uuid('user_id')
+      .notNull()
+      .references(() => users.id, { onDelete: 'cascade' }),
+    /** sha256 of the device token; the token can only report playback. */
+    tokenHash: text('token_hash').notNull().unique(),
+    platform: text('platform').$type<'android' | 'ios'>().notNull(),
+    name: varchar('name', { length: 100 }).notNull(),
+    lastSeenAt: timestamp('last_seen_at', { withTimezone: true }),
+    createdAt: createdAt(),
+  },
+  (t) => [index('devices_user_idx').on(t.userId)],
+);
+
 /** Recent plays per user, for "Recently played" on profiles. Trimmed to the latest LISTEN_HISTORY_LIMIT. */
 export const listens = pgTable(
   'listens',