Gate thin app-server integration for Code Bridge

[shiny-code-bot]

Current Status

State: Proposed final integration stage for #36. Multi-agent review warned that app-server should not host the high-volume telemetry/control plane by default because of Desktop compatibility, protocol churn, and stability risks.

Acceptance Criteria

• Explicitly decide whether app-server integration is needed after the standalone service/client/MCP path works.
• If needed, define only narrow experimental v2 methods such as bridge status/read, subscription preference, or bounded event list; app producer telemetry must not flow through app-server by default.
• Existing remoteControl/* semantics remain unchanged.
• App-server README/Desktop compatibility guidance is updated if behavior changes.
• Schema fixtures are regenerated and reviewed for intended-only diffs.
• Absent bridge service returns a clear unavailable status.

Target Surface

codex-rs/app-server-protocol, codex-rs/app-server, and app-server docs only after #45-#47 are proven.

Validation Gate

just write-app-server-schema; just test -p codex-app-server-protocol; targeted just test -p codex-app-server; Desktop compatibility gate from app-server README.

Risks

This is where bridge work can destabilize upstream-shaped app-server/desktop contracts. Keep the integration boring, experimental, and late.

Finish Line

App-server can discover or consume Code Bridge status/events through a narrow experimental surface only after the standalone bridge protocol and service prove stable.

[shiny-code-bot]

Completed by PR #112: #112

What landed:

• Added experimental codeBridge/status/read app-server method.
• Reads Code Bridge descriptor and status only; it does not make app-server a telemetry/control participant.
• Preserves existing remoteControl/* behavior.
• Returns clear unavailable reasons for missing/invalid descriptor, unreachable service, unsupported endpoint, and invalid status payload.
• Regenerated/reviewed stable app-server schema fixtures so experimental Code Bridge types do not leak into stable schema output.
• Updated app-server README compatibility notes.

Validation:

• cargo test -p codex-app-server-protocol --test schema_fixtures --no-fail-fast
• cargo test -p codex-app-server-protocol code_bridge_status_read_is_marked_experimental --no-fail-fast
• cargo test -p codex-app-server-protocol client_request_serialization_scope --no-fail-fast
• cargo test -p codex-code-bridge-client --no-fail-fast
• cargo test -p codex-app-server code_bridge --no-fail-fast
• affected cargo check for app-server/protocol/code-bridge crates
• PR checks passed before merge