Refactor OpenAI provider identity so OpenAI remains the canonical provider for API-key and OAuth-backed flows while legacy openai-codex state is doctor/migration-only.
Keeps OpenAI Codex Responses as an API/transport class rather than a provider identity, moves auth aliases through providerAuthAliases, updates doctor repair sequencing for old auth/profile state, and refreshes tests/docs around the canonical OpenAI behavior.
* TypeScript: add extensions to tsconfig and fix type errors
- Add extensions/**/* to tsconfig.json includes
- Export ProviderAuthResult, AnyAgentTool from plugin-sdk
- Fix optional chaining for messageActions across channels
- Add missing type imports (MSTeamsConfig, GroupPolicy, etc.)
- Add type annotations for provider auth handlers
- Fix undici/fetch type compatibility in zalo proxy
- Correct ChannelAccountSnapshot property usage
- Add type casts for tool registrations
- Extract usage view styles and types to separate files
* TypeScript: fix optional debug calls and handleAction guards
