fix: fence worker retries and object publication

migrations/015_worker_attempt_leases.sql

@@ -0,0 +1,17 @@
+ALTER TABLE tasks
+  ADD COLUMN IF NOT EXISTS processing_attempt BIGINT NOT NULL DEFAULT 0,
+  ADD COLUMN IF NOT EXISTS lease_owner UUID,
+  ADD COLUMN IF NOT EXISTS lease_until TIMESTAMPTZ;
+
+ALTER TABLE task_files
+  ADD COLUMN IF NOT EXISTS processing_attempt BIGINT NOT NULL DEFAULT 0,
+  ADD COLUMN IF NOT EXISTS lease_owner UUID,
+  ADD COLUMN IF NOT EXISTS lease_until TIMESTAMPTZ;
+
+CREATE INDEX IF NOT EXISTS idx_tasks_processing_lease
+  ON tasks(lease_until)
+  WHERE status = 'processing';
+
+CREATE INDEX IF NOT EXISTS idx_task_files_processing_lease
+  ON task_files(task_id, lease_until)
+  WHERE status = 'processing';