Prioritize newest AI jobs

internal/migrate/sql/003_ai_jobs_newest_first.up.sql

@@ -0,0 +1,5 @@
+DROP INDEX IF EXISTS ai_jobs_pending_claim_idx;
+
+CREATE INDEX IF NOT EXISTS ai_jobs_pending_claim_idx
+    ON ai_jobs (status, priority DESC, scheduled_at DESC, created_at DESC)
+    WHERE status = 'pending';

internal/store/store.go

@@ -330,7 +330,7 @@ WITH picked AS (
     AND scheduled_at <= NOW()
     AND (cardinality($1::text[]) = 0 OR task_type = ANY($1::text[]))
     AND (cardinality($2::text[]) = 0 OR model_profile = ANY($2::text[]))
-  ORDER BY priority DESC, scheduled_at ASC, created_at ASC
+  ORDER BY priority DESC, scheduled_at DESC, created_at DESC
   LIMIT $3
   FOR UPDATE SKIP LOCKED
 )

migrations/003_ai_jobs_newest_first.down.sql

@@ -0,0 +1,5 @@
+DROP INDEX IF EXISTS ai_jobs_pending_claim_idx;
+
+CREATE INDEX IF NOT EXISTS ai_jobs_pending_claim_idx
+    ON ai_jobs (status, priority DESC, scheduled_at ASC, created_at ASC)
+    WHERE status = 'pending';

migrations/003_ai_jobs_newest_first.up.sql

@@ -0,0 +1,5 @@
+DROP INDEX IF EXISTS ai_jobs_pending_claim_idx;
+
+CREATE INDEX IF NOT EXISTS ai_jobs_pending_claim_idx
+    ON ai_jobs (status, priority DESC, scheduled_at DESC, created_at DESC)
+    WHERE status = 'pending';