feat(scheduler): add durability — re-queue surviving LLM tasks on startup

scripts/task_scheduler.py

@@ -91,6 +91,9 @@ class TaskScheduler:
         except Exception:
             self._available_vram = 999.0
 
+        # Durability: reload surviving 'queued' LLM tasks from prior run
+        self._load_queued_tasks()
+
     def enqueue(self, task_id: int, task_type: str, job_id: int,
                 params: Optional[str]) -> None:
         """Add an LLM task to the scheduler queue.
@@ -186,6 +189,26 @@ class TaskScheduler:
                 self._reserved_vram -= self._budgets.get(task_type, 0.0)
             self._wake.set()
 
+    def _load_queued_tasks(self) -> None:
+        """Load pre-existing queued LLM tasks from SQLite into deques (called once in __init__)."""
+        llm_types = sorted(LLM_TASK_TYPES)  # sorted for deterministic SQL params in logs
+        placeholders = ",".join("?" * len(llm_types))
+        conn = sqlite3.connect(self._db_path)
+        rows = conn.execute(
+            f"SELECT id, task_type, job_id, params FROM background_tasks"
+            f" WHERE status='queued' AND task_type IN ({placeholders})"
+            f" ORDER BY created_at ASC",
+            llm_types,
+        ).fetchall()
+        conn.close()
+
+        for row_id, task_type, job_id, params in rows:
+            q = self._queues.setdefault(task_type, deque())
+            q.append(TaskSpec(row_id, job_id, params))
+
+        if rows:
+            logger.info("Scheduler: resumed %d queued task(s) from prior run", len(rows))
+
 
 # ── Singleton ─────────────────────────────────────────────────────────────────
 

tests/test_task_scheduler.py

@@ -371,3 +371,56 @@ def test_reset_scheduler_cleans_up(tmp_db):
     # After reset, get_scheduler creates a fresh instance
     s2 = get_scheduler(tmp_db, _noop_run_task)
     assert s2 is not s
+
+
+def test_durability_loads_queued_llm_tasks_on_startup(tmp_db):
+    """Scheduler loads pre-existing queued LLM tasks into deques at construction."""
+    from scripts.db import insert_task
+
+    # Pre-insert queued rows simulating a prior run
+    id1, _ = insert_task(tmp_db, "cover_letter", 1)
+    id2, _ = insert_task(tmp_db, "company_research", 2)
+
+    s = TaskScheduler(tmp_db, _noop_run_task)
+
+    assert len(s._queues.get("cover_letter", [])) == 1
+    assert s._queues["cover_letter"][0].id == id1
+    assert len(s._queues.get("company_research", [])) == 1
+    assert s._queues["company_research"][0].id == id2
+
+
+def test_durability_excludes_non_llm_queued_tasks(tmp_db):
+    """Non-LLM queued tasks are not loaded into the scheduler deques."""
+    from scripts.db import insert_task
+
+    insert_task(tmp_db, "discovery", 0)
+    insert_task(tmp_db, "email_sync", 0)
+
+    s = TaskScheduler(tmp_db, _noop_run_task)
+
+    assert "discovery" not in s._queues or len(s._queues["discovery"]) == 0
+    assert "email_sync" not in s._queues or len(s._queues["email_sync"]) == 0
+
+
+def test_durability_preserves_fifo_order(tmp_db):
+    """Queued tasks are loaded in created_at (FIFO) order."""
+    conn = sqlite3.connect(tmp_db)
+    # Insert with explicit timestamps to control order
+    conn.execute(
+        "INSERT INTO background_tasks (task_type, job_id, params, status, created_at)"
+        " VALUES (?,?,?,?,?)", ("cover_letter", 1, None, "queued", "2026-01-01 10:00:00")
+    )
+    conn.execute(
+        "INSERT INTO background_tasks (task_type, job_id, params, status, created_at)"
+        " VALUES (?,?,?,?,?)", ("cover_letter", 2, None, "queued", "2026-01-01 09:00:00")
+    )
+    conn.commit()
+    ids = [r[0] for r in conn.execute(
+        "SELECT id FROM background_tasks ORDER BY created_at ASC"
+    ).fetchall()]
+    conn.close()
+
+    s = TaskScheduler(tmp_db, _noop_run_task)
+
+    loaded_ids = [t.id for t in s._queues["cover_letter"]]
+    assert loaded_ids == ids