[codex] Apply preferred Codex++ defaults

[Dautlers]

Summary

• Switch Codex++ manager, injected UI, backend notices, and installer naming to English-facing copy.
• Keep Conversation Timeline disabled by default and force it off in the injected renderer, including saved/backend settings overrides.
• Preserve the session-proven reliability tweaks: macOS DevTools port fallback when the requested port is busy and the DOM-root guard for injected UI mounting.
• Update tests and macOS packaging names to match the English Codex++ Manager behavior.

Validation

• node --check assets/inject/renderer-inject.js
• git diff --check
• npm run check
• target/debug/deps/launcher-baefab9214d7638f ports_ --nocapture (2 passed)
• target/debug/deps/cdp_bridge-3ae95d85fe9ac652 --nocapture (48 passed)
• BINARY_DIR="$PWD/target/release" bash scripts/installer/macos/package-dmg.sh 1.2.6 arm64
• codesign --verify --deep --strict for both staged macOS apps

Notes

This PR carries forward the settings/preferences from a local Codex++ install session: English UI, no right-side Conversation Timeline line/circles, and more resilient startup/injection behavior on macOS.