fix: revoke gamification points on recording delete + fix comment collection

- deleteRecording now queues revokePoints for RECORDING_CREATE (and
  RECORDING_FEATURED if applicable) before deleting a published recording,
  so leaderboard points are correctly removed
- Fix comment stat/achievement queries using collection "recordings" instead
  of "videos" — comments are stored under collection "videos", so the count
  was always 0, breaking COMMENT_CREATE stats and social achievements

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

packages/backend/src/graphql/resolvers/recordings.ts

@@ -251,6 +251,28 @@ builder.mutationField("deleteRecording", (t) =>
       if (!existing[0]) throw new GraphQLError("Recording not found");
       if (existing[0].user_id !== ctx.currentUser.id) throw new GraphQLError("Forbidden");
 
+      if (existing[0].status === "published") {
+        await gamificationQueue.add("revokePoints", {
+          job: "revokePoints",
+          userId: ctx.currentUser.id,
+          action: "RECORDING_CREATE",
+          recordingId: args.id,
+        });
+        if (existing[0].featured) {
+          await gamificationQueue.add("revokePoints", {
+            job: "revokePoints",
+            userId: ctx.currentUser.id,
+            action: "RECORDING_FEATURED",
+            recordingId: args.id,
+          });
+        }
+        await gamificationQueue.add("checkAchievements", {
+          job: "checkAchievements",
+          userId: ctx.currentUser.id,
+          category: "content",
+        });
+      }
+
       await ctx.db.delete(recordings).where(eq(recordings.id, args.id));
 
       return true;