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>

server/src/routes/bets.ts

@@ -103,8 +103,8 @@ betsRouter.post('/place', rateLimit(60_000, 10), async (c) => {
       odds: bet.oddsAtPlacement,
       potentialPayout: bet.potentialPayout,
     })
-  } catch (err: any) {
-    return c.json({ error: err.message }, 400)
+  } catch (err: unknown) {
+    return c.json({ error: err instanceof Error ? err.message : String(err) }, 400)
   }
 })