fix(types): replace all as any with proper type assertions

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>

src/components/tasks/RemoteSessionDetailDialog.tsx

@@ -122,7 +122,8 @@ function UltraplanSessionDetail({
     let lastBlock: { name: string; input: unknown } | null = null
     for (const msg of session.log) {
       if (msg.type !== 'assistant') continue
-      for (const block of msg.message.content) {
+      const content = msg.message?.content ?? []
+      for (const block of content as Array<{type: string; name: string; input: unknown}>) {
         if (block.type !== 'tool_use') continue
         calls++
         lastBlock = block