fix: add delay after AudioContext resume and schedule offset

frontend/src/components/Settings.svelte

@@ -46,6 +46,8 @@
       // Resume context if suspended (required by browsers on first interaction)
       if (ctx.state === 'suspended') {
         await ctx.resume()
+        // Wait a frame for currentTime to update after resume
+        await new Promise(resolve => setTimeout(resolve, 50))
       }
       const oscillator = ctx.createOscillator()
       const gainNode = ctx.createGain()
@@ -56,11 +58,13 @@
       oscillator.frequency.value = frequency
       oscillator.type = type
       
-      gainNode.gain.setValueAtTime(0.3, ctx.currentTime)
-      gainNode.gain.exponentialRampToValueAtTime(0.01, ctx.currentTime + duration)
+      // Use small offset to ensure sound is scheduled in the future
+      const startTime = ctx.currentTime + 0.01
+      gainNode.gain.setValueAtTime(0.3, startTime)
+      gainNode.gain.exponentialRampToValueAtTime(0.01, startTime + duration)
       
-      oscillator.start(ctx.currentTime)
-      oscillator.stop(ctx.currentTime + duration)
+      oscillator.start(startTime)
+      oscillator.stop(startTime + duration)
     } catch (e) {
       console.error('Failed to play sound:', e)
       alert('Sound error: ' + e.message)