fix(types): clean type fixes across 92 files

Apply proper TypeScript type corrections without any unsafe casts:
- Fix unknown/never/{} types from decompilation
- Correct function signatures and parameter types
- Add missing type declarations and interfaces
- Fix Ink component prop types
- Update API client/provider type annotations

Test files with mock data casts are included as-is (acceptable pattern).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/components/Spinner.tsx

@@ -63,6 +63,15 @@ type Props = {
   pauseStartTimeRef: React.RefObject<number | null>
   spinnerTip?: string
   responseLengthRef: React.RefObject<number>
+  apiMetricsRef?: React.RefObject<
+    Array<{
+      ttftMs: number;
+      firstTokenTime: number;
+      lastTokenTime: number;
+      responseLengthBaseline: number;
+      endResponseLength: number;
+    }>
+  >
   overrideColor?: keyof Theme | null
   overrideShimmerColor?: keyof Theme | null
   overrideMessage?: string | null