Postgres engine: scheduler + outbox — schedule (validation triad, the pg-owned @every-only parser, upsert over the schedule table), unschedule, run_schedules (leadership via the engine's lock machinery on __alkstore_scheduler with a per-instance owner token, in-sleep lease renewals, the row-locked FOR UPDATE tick in one pool tx — fire enqueues + boundary advance + soonest read commit together — the 64-boundary catch-up cap with skip-forward, clean stop / Err(LeadershipLost) arms), outbox (validated constructor, enqueue into the derived __alkstore_outbox:{name} with the 60/5/5 stamps + max_attempts override, run_once ack/retry-curve/false over the ordinary claim machinery, no engine-issued heartbeat) (task pg-engine-scheduler-outbox)

alkstore-postgres/src/lock.rs

@@ -66,7 +66,7 @@ fn table(schema: &str, name: &str) -> String {
 /// expiry-delete + insert + read-back race window is closed by the
 /// PK constraint — a concurrent grant of the same name either
 /// lands first or reads as foreign).
-async fn lock_acquire(
+pub(crate) async fn lock_acquire(
     client: &tokio_postgres::Client,
     schema: &str,
     name: &str,
@@ -166,6 +166,29 @@ impl std::fmt::Debug for PgLockHandle {
     }
 }
 
+impl PgLockHandle {
+    /// The engine-internal constructor (the SQLite twin's
+    /// `SqliteLockHandle::new_internal` shape): the scheduler's
+    /// leadership lease on the reserved name — `try_lock`'s entry
+    /// validation would reject the reserved name, so the engine's own
+    /// holder builds the handle directly after its own acquire.
+    pub(crate) fn new_internal(
+        name: String,
+        owner: String,
+        pool: Pool,
+        schema: String,
+        closed: Arc<AtomicBool>,
+    ) -> Self {
+        Self {
+            name,
+            owner,
+            pool,
+            schema,
+            closed,
+        }
+    }
+}
+
 impl Lock for PgLockHandle {
     fn name(&self) -> &str {
         &self.name