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- Revoke RECORDING_CREATE points when a recording is unpublished (published → draft)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/graphql/resolvers/comments.ts

@@ -3,8 +3,8 @@ import { builder } from "../builder";
 import { CommentType, AdminCommentListType } from "../types/index";
 import { comments, users } from "../../db/schema/index";
 import { eq, and, desc, ilike, count } from "drizzle-orm";
-import { awardPoints, checkAchievements } from "../../lib/gamification";
 import { requireOwnerOrAdmin, requireAdmin } from "../../lib/acl";
+import { gamificationQueue } from "../../queues/index";
 
 builder.queryField("commentsForVideo", (t) =>
   t.field({
@@ -59,10 +59,16 @@ builder.mutationField("createCommentForVideo", (t) =>
         })
         .returning();
 
-      // Gamification (non-blocking)
-      awardPoints(ctx.db, ctx.currentUser.id, "COMMENT_CREATE")
-        .then(() => checkAchievements(ctx.db, ctx.currentUser!.id, "social"))
-        .catch((e) => console.error("Gamification error on comment:", e));
+      await gamificationQueue.add("awardPoints", {
+        job: "awardPoints",
+        userId: ctx.currentUser.id,
+        action: "COMMENT_CREATE",
+      });
+      await gamificationQueue.add("checkAchievements", {
+        job: "checkAchievements",
+        userId: ctx.currentUser.id,
+        category: "social",
+      });
 
       const user = await ctx.db
         .select({