API: follower lists, blocking, reports, admin; drop Spotify sign-in

- Followers/following lists (paginated), 'follows you', remove a follower
- Blocking severs follows both ways and hides each user from the other
  (profile 404s, search, follows); the blocker sees activity hidden
- Reports for moderation (App Store guideline 1.2)
- First account on a server becomes admin; admins see the report queue,
  resolve reports, and suspend accounts (signs out, blocks login, hides
  the profile, stops sharing). set-role script to promote/demote
- users.onboardedAt drives first-run onboarding; existing accounts are
  backfilled as already onboarded. Empty PATCH /me no longer 500s
- Remove Spotify account sign-in and polling: Spotify caps new apps at 5
  accounts, so Spotify arrives via its Last.fm/ListenBrainz link or the
  Android reader. App-level catalog search stays for exact links
- Shared: QR code generation and profile-link parsing (verified with jsQR)
- Integration test timeout raised; password hashing is slow by design

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

apps/api/package.json

@@ -14,7 +14,9 @@
     "test": "vitest run",
     "test:unit": "vitest run --project unit",
     "test:watch": "vitest",
-    "start:migrate": "node dist/db/migrate.js"
+    "start:migrate": "node dist/db/migrate.js",
+    "admin:promote": "tsx src/scripts/set-role.ts admin",
+    "admin:demote": "tsx src/scripts/set-role.ts user"
   },
   "dependencies": {
     "@fastify/cookie": "^11.1.2",