Revert "fix: enforce task-wait checkpoint lifecycle and stop UI probe from rescanning tasks table"

This reverts commit d502d66c60.

opc/database/store.py

@@ -1620,7 +1620,6 @@ class OPCStore:
             CREATE INDEX IF NOT EXISTS idx_tasks_project_status_created ON tasks(project_id, status, created_at);
             CREATE INDEX IF NOT EXISTS idx_tasks_project_priority_created ON tasks(project_id, priority, created_at);
             CREATE INDEX IF NOT EXISTS idx_tasks_parent ON tasks(parent_id);
-            CREATE INDEX IF NOT EXISTS idx_tasks_session ON tasks(session_id);
             CREATE INDEX IF NOT EXISTS idx_messages_task ON agent_messages(task_id);
             CREATE INDEX IF NOT EXISTS idx_messages_status ON agent_messages(status);
             CREATE INDEX IF NOT EXISTS idx_messages_timestamp ON agent_messages(timestamp);
@@ -2793,24 +2792,6 @@ class OPCStore:
         await self.hydrate_task_work_item_links(tasks)
         return tasks
 
-    async def get_tasks_by_session_id(
-        self,
-        session_id: str,
-        project_id: str | None = None,
-    ) -> list[Task]:
-        assert self._db
-        query = "SELECT * FROM tasks WHERE session_id = ?"
-        params: list[Any] = [session_id]
-        if project_id:
-            query += " AND project_id = ?"
-            params.append(project_id)
-        query += " ORDER BY priority ASC, created_at ASC"
-        async with self._db.execute(query, params) as cursor:
-            rows = await cursor.fetchall()
-            tasks = [self._row_to_task(row, cursor.description) for row in rows]
-        await self.hydrate_task_work_item_links(tasks)
-        return tasks
-
     async def update_task_status(self, task_id: str, status: TaskStatus) -> None:
         assert self._db
         await self._db.execute("UPDATE tasks SET status = ? WHERE id = ?", (status.value, task_id))