fix(codex-api): treat invalid_prompt as non-retryable (#9400)

**Goal**: Prevent response.failed events with `invalid_prompt` from
being treated as retryable errors so the UI shows the actual error
message instead of continually retrying.

**Before**: Codex would continue to retry despite the prompt being
marked as disallowed
**After**: Codex will stop retrying once prompt is marked disallowed

codex-rs/core/src/api_bridge.rs

@@ -28,6 +28,7 @@ pub(crate) fn map_api_error(err: ApiError) -> CodexErr {
             url: None,
             request_id: None,
         }),
+        ApiError::InvalidRequest { message } => CodexErr::InvalidRequest(message),
         ApiError::Transport(transport) => match transport {
             TransportError::Http {
                 status,