feat(app-server): enforce managed remote control disable (#27961)

## Why

Managed deployments need a reliable deny gate for remote control.
Persisted enablement and explicit startup requests currently remain able
to start the transport, while the removed `features.remote_control` key
is intentionally only a compatibility no-op.

This adds a dedicated requirement that administrators can use to force
remote control off without deleting the user's persisted preference.
Removing the requirement and restarting restores the prior choice.

## What Changed

- Added top-level `allow_remote_control` requirements parsing, sourced
layer precedence, debug output, and `configRequirements/read` exposure
as `allowRemoteControl`.
- Added a typed transport policy captured from the startup requirements
snapshot. Managed disable forces the initial state to disabled and
prevents enrollment, refresh, connection, and persisted-preference
mutation.
- Rejected every `remoteControl/*` RPC before parameter deserialization
with JSON-RPC `-32600` and `remote control is disabled by managed
requirements`.
- Preserved the existing disabled status notification and the previous
behavior when the requirement is `true` or omitted.
- Regenerated app-server protocol schemas and documented the new
requirement.

## Verification

- Confirmed all remote-control RPCs, including a malformed request,
return the managed-policy error while the initial status notification
remains `disabled`.
- Confirmed explicit ephemeral startup and persisted enablement make no
backend connection and leave the SQLite preference unchanged.
- Confirmed `allow_remote_control = true` does not enable or block
remote control and `configRequirements/read` returns
`allowRemoteControl: false` for the deny policy.

Related issue: N/A (managed-policy hardening).

codex-rs/app-server/src/request_processors/config_processor.rs

@@ -364,6 +364,7 @@ fn map_requirements_toml_to_api(requirements: ConfigRequirementsToml) -> ConfigR
         }),
         allow_managed_hooks_only: requirements.allow_managed_hooks_only,
         allow_appshots: requirements.allow_appshots,
+        allow_remote_control: requirements.allow_remote_control,
         computer_use: requirements
             .computer_use
             .map(map_computer_use_requirements_to_api),
@@ -618,6 +619,16 @@ mod tests {
         assert_eq!(mapped.hooks, None);
     }
 
+    #[test]
+    fn requirements_api_includes_allow_remote_control() {
+        let mapped = map_requirements_toml_to_api(ConfigRequirementsToml {
+            allow_remote_control: Some(false),
+            ..ConfigRequirementsToml::default()
+        });
+
+        assert_eq!(mapped.allow_remote_control, Some(false));
+    }
+
     #[test]
     fn requirements_api_includes_computer_use_requirements() {
         let mapped = map_requirements_toml_to_api(ConfigRequirementsToml {