Claude API on Vertex AI (Cloud Code Assist) rejects nested anyOf schemas
as invalid JSON Schema draft 2020-12. This change:
- Add tryFlattenLiteralAnyOf() to convert Type.Union([Type.Literal(...)])
patterns from anyOf with const values to flat enum arrays
- Update stringEnum helper in bash-tools to use Type.Unsafe with flat enum
- Flatten BrowserActSchema from discriminated union to single object
- Simplify TelegramToolSchema to use Type.String() for IDs
Fixes 400 errors when sending messages through WhatsApp/Telegram providers.