Remove CSV-backed agent jobs (#34413)

## What changed

- Remove the `spawn_agents_on_csv` and `report_agent_job_result` tools and their agent-job runtime and state models.
- Drop the legacy `agent_jobs` and `agent_job_items` tables during state database migration.
- Keep `features.enable_fanout` and `agents.job_max_runtime_seconds` accepted as no-op compatibility settings while omitting them from the generated configuration schema.

## Testing

- Verify upgrades remove both legacy agent-job tables.
- Verify the removed feature and configuration keys still parse without taking effect.

GitOrigin-RevId: 8cc3337da78c67162229f02f40a747f503542646

codex-rs/thread-manager-sample/src/main.rs

@@ -245,7 +245,6 @@ fn new_config(model: Option<String>, arg0_paths: Arg0DispatchPaths) -> anyhow::R
         agent_max_threads: Some(6),
         agent_default_subagent_model: None,
         agent_default_subagent_reasoning_effort: None,
-        agent_job_max_runtime_seconds: None,
         agent_interrupt_message_enabled: false,
         agent_max_depth: 1,
         agent_roles: BTreeMap::new(),