Eliminate unsafe `as any` casts across 21 non-test source files,
replacing them with specific type annotations:
- Bridge transport: use StdoutMessage type for write/writeBatch calls
- print.ts: type msg.request as Record<string, unknown> for unknown
SDK control subtypes; use StdoutMessage for output.enqueue()
- API providers (openai/grok/gemini): import ChatCompletion types,
type streams as AsyncIterable<ChatCompletionChunk>, type request
bodies as ChatCompletionCreateParamsStreaming
- Computer use executor: use Partial<ResolvePrepareCaptureResult>
for cross-platform screenshot result
- Components: replace Ink color string casts with proper typing
- Win32 bridge: type stdin as Writable after null check
All 2453 tests pass with 0 failures.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
