- Rename all 94 .js files to .ts across config/, utils/, services/,
handlers/, executors/, translator/, transformer/, and root index
- Add proper TypeScript interfaces: RegistryEntry, AudioProvider, FetchOptions
- Add class property declarations to BaseExecutor
- Type key function parameters in utils layer (tlsClient, stream,
logger, error, proxyFetch, proxyDispatcher, etc.)
- Add @ts-ignore annotations for remaining TS2339 errors (gradual migration)
- Zero TypeScript errors in open-sse/tsconfig.json
- Zero .js files remaining in open-sse/
