Add thread message delivery

codex-rs/state/migrations/0026_thread_messages.sql

@@ -0,0 +1,77 @@
+ALTER TABLE thread_timers RENAME TO thread_timers_old;
+
+CREATE TABLE thread_timers (
+    id TEXT PRIMARY KEY,
+    thread_id TEXT NOT NULL,
+    source TEXT NOT NULL,
+    client_id TEXT NOT NULL,
+    trigger_json TEXT NOT NULL,
+    content TEXT NOT NULL,
+    instructions TEXT,
+    meta_json TEXT NOT NULL,
+    delivery TEXT NOT NULL,
+    created_at INTEGER NOT NULL,
+    next_run_at INTEGER,
+    last_run_at INTEGER,
+    pending_run INTEGER NOT NULL
+);
+
+INSERT INTO thread_timers (
+    id,
+    thread_id,
+    source,
+    client_id,
+    trigger_json,
+    content,
+    instructions,
+    meta_json,
+    delivery,
+    created_at,
+    next_run_at,
+    last_run_at,
+    pending_run
+)
+SELECT
+    id,
+    thread_id,
+    source,
+    client_id,
+    trigger_json,
+    prompt,
+    NULL,
+    '{}',
+    delivery,
+    created_at,
+    next_run_at,
+    last_run_at,
+    pending_run
+FROM thread_timers_old;
+
+DROP TABLE thread_timers_old;
+
+CREATE INDEX idx_thread_timers_thread_created
+    ON thread_timers(thread_id, created_at, id);
+
+CREATE INDEX idx_thread_timers_thread_pending
+    ON thread_timers(thread_id, pending_run, created_at, id);
+
+CREATE INDEX idx_thread_timers_thread_next_run
+    ON thread_timers(thread_id, next_run_at);
+
+CREATE TABLE thread_messages (
+    seq INTEGER PRIMARY KEY,
+    id TEXT NOT NULL UNIQUE,
+    thread_id TEXT NOT NULL,
+    source TEXT NOT NULL,
+    content TEXT NOT NULL,
+    instructions TEXT,
+    meta_json TEXT NOT NULL,
+    delivery TEXT NOT NULL,
+    queued_at INTEGER NOT NULL
+);
+
+CREATE INDEX thread_messages_thread_order_idx
+    ON thread_messages(thread_id, queued_at, seq);
+
+CREATE INDEX thread_messages_thread_delivery_order_idx
+    ON thread_messages(thread_id, delivery, queued_at, seq);