feat: gamification queue with deduplication and unpublish revoke

- Add migration 0004: partial unique index on user_points (user_id, action, recording_id)
  for RECORDING_CREATE and RECORDING_FEATURED to prevent earn-on-republish farming
- Add revokePoints() to gamification lib; awardPoints() now uses onConflictDoNothing
- Add gamificationQueue (BullMQ) with 3-attempt exponential backoff
- Add gamification worker handling awardPoints, revokePoints, checkAchievements jobs
- Move all inline gamification calls in recordings + comments resolvers to queue
- Revoke RECORDING_CREATE points when a recording is unpublished (published → draft)
- Register gamification worker at server startup alongside mail worker

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

packages/backend/src/queues/index.ts

@@ -5,13 +5,21 @@ import { logger } from "../lib/logger.js";
 const log = logger.child({ component: "queues" });
 
 export const mailQueue = new Queue("mail", { connection: redisConnectionOpts });
-
 mailQueue.on("error", (err) => {
   log.error({ queue: "mail", err: err.message }, "Queue error");
 });
 
-log.info("Mail queue initialized");
+export const gamificationQueue = new Queue("gamification", {
+  connection: redisConnectionOpts,
+  defaultJobOptions: { attempts: 3, backoff: { type: "exponential", delay: 2000 } },
+});
+gamificationQueue.on("error", (err) => {
+  log.error({ queue: "gamification", err: err.message }, "Queue error");
+});
+
+log.info("Queues initialized");
 
 export const queues: Record<string, Queue> = {
   mail: mailQueue,
+  gamification: gamificationQueue,
 };