fix: replace all silent .catch(() => {}) with console.warn (BUG-F2)

13 silent catch handlers replaced with descriptive console.warn logging
across 6 frontend files. No silent error swallowing remains.

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

frontend/src/game/audio/context.ts

@@ -29,7 +29,7 @@ export function initCtx() {
 export function getCtx(): AudioContext {
   if (!ctx) initCtx()
   if (ctx!.state === 'suspended') {
-    ctx!.resume().catch(() => {})
+    ctx!.resume().catch(err => console.warn('[Audio] context resume failed:', err))
   }
   return ctx!
 }