Fix: restore Codex desktop compatibility

[xIGBClutchIx]

Summary

This restores compatibility with newer Codex desktop builds so Pocodex once again exposes git-backed desktop controls like Toggle Terminal.

What changed

• add the platform-family main RPC expected by current Codex desktop git workers
• detect whether the current workspace is git-backed and propagate that host kind through the app-server bridge, CLI runtime, and bootstrap payload
• expose the newer browser bridge methods that current Codex bundles expect, including shared-object snapshot reads and system-theme/menu hooks
• seed and update the host_config and remote_connections shared-object snapshots used by the current bundle
• add regression coverage for the git worker RPC, host-kind resolution, bridge compatibility methods, and the related bootstrap timer behavior

Root cause

Recent Codex desktop builds changed the browser-shell and desktop-worker contracts Pocodex has to satisfy:

• the desktop git worker now asks the host for a platform-family RPC
• the webview now reads host_config from the shared-object snapshot bridge during startup
• without those compatibility hooks, git stable-metadata does not settle correctly and the workspace is not treated as git-backed
• once that happens, desktop-only git controls such as Toggle Terminal disappear

Impact

• Toggle Terminal and other git-backed desktop controls are available again in Pocodex
• local workspaces are classified correctly as git or local during bootstrap
• the desktop/browser compatibility surface is covered by focused regression tests so future Codex bundle updates are easier to catch

Validation

• pnpm run check:commit
• pnpm exec vitest run test/bootstrap-script.test.ts test/app-server-bridge-basic.test.ts test/app-server-bridge-workers.test.ts test/app-server-bridge-host-config.test.ts test/codex-desktop-git-worker.test.ts
• live local verification that host_config.kind resolves to git and the UI exposes Toggle terminal