fix: make gamification calls non-blocking so errors don't fail core mutations

awardPoints/checkAchievements were awaited inline, so any gamification error
(DB constraint, missing table, etc.) would propagate as INTERNAL_SERVER_ERROR
on comment creation, recording plays, etc. Now they run fire-and-forget with
error logging, so the core action always succeeds.

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

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

@@ -59,9 +59,10 @@ builder.mutationField("createCommentForVideo", (t) =>
         })
         .returning();
 
-      // Gamification
-      await awardPoints(ctx.db, ctx.currentUser.id, "COMMENT_CREATE");
-      await checkAchievements(ctx.db, ctx.currentUser.id, "social");
+      // 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));
 
       const user = await ctx.db
         .select({