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/state/src/runtime/remote_control.rs

@@ -330,7 +330,14 @@ mod tests {
             .await
             .expect("create codex home");
         let old_state_migrator = Migrator {
-            migrations: Cow::Owned(STATE_MIGRATOR.migrations[..36].to_vec()),
+            migrations: Cow::Owned(
+                STATE_MIGRATOR
+                    .migrations
+                    .iter()
+                    .filter(|migration| migration.version <= 36)
+                    .cloned()
+                    .collect(),
+            ),
             ignore_missing: false,
             locking: true,
             no_tx: false,