refactor: eliminate any types across server and TTS worker

- app.ts: type serveFile context parameter as Hono Context
- bets.ts: replace catch(err: any) with err: unknown + narrowing
- fight-loop.ts: type pickMatchup style as union literal, replace
  as any casts with proper result type
- tts-worker.ts: import KokoroTTS type, use ProgressInfo inference

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

frontend/src/game/tts-worker.ts

@@ -1,7 +1,9 @@
 // Web Worker for Kokoro TTS — runs ONNX neural network inference off the main thread.
 // This prevents the 1-5 second freezes that occur when generate() runs on the UI thread.
 
-let tts: any = null
+import type { KokoroTTS } from 'kokoro-js'
+
+let tts: KokoroTTS | null = null
 
 self.addEventListener('message', async (e: MessageEvent) => {
   const msg = e.data
@@ -13,8 +15,8 @@ self.addEventListener('message', async (e: MessageEvent) => {
         tts = await KokoroTTS.from_pretrained('onnx-community/Kokoro-82M-ONNX', {
           dtype: 'q8',
           device: null,
-          progress_callback: (p: any) => {
-            if (p.progress !== undefined) {
+          progress_callback: (p) => {
+            if ('progress' in p && typeof p.progress === 'number') {
               self.postMessage({ type: 'progress', progress: p.progress })
             }
           },