fix: embed DECAY_LAMBDA as SQL literal to avoid pg type inference failure

PostgreSQL cannot resolve the type of a parameterized $1 = 0.005 in
-$1 * EXTRACT(EPOCH ...) and fails with an operator type error. Using
sql.raw() embeds the constant directly in the query string so userId
is the only parameter.

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

packages/backend/src/lib/gamification.ts

@@ -62,7 +62,7 @@ export async function revokePoints(
 export async function calculateWeightedScore(db: DB, userId: string): Promise<number> {
   const result = await db.execute(sql`
     SELECT SUM(
-      points * EXP(-${DECAY_LAMBDA} * EXTRACT(EPOCH FROM (NOW() - date_created)) / 86400)
+      points * EXP(${sql.raw(String(-DECAY_LAMBDA))} * EXTRACT(EPOCH FROM (NOW() - date_created)) / 86400)
     ) as weighted_score
     FROM user_points
     WHERE user_id = ${userId}

packages/backend/src/queues/workers/gamification.ts

@@ -17,7 +17,10 @@ export function startGamificationWorker(): Worker {
     "gamification",
     async (bullJob) => {
       const data = bullJob.data as GamificationJobData;
-      log.info({ jobId: bullJob.id, job: data.job, userId: data.userId }, "Processing gamification job");
+      log.info(
+        { jobId: bullJob.id, job: data.job, userId: data.userId },
+        "Processing gamification job",
+      );
 
       switch (data.job) {
         case "awardPoints":