Tune hero peaks and add louder scope switch click

main.py

@@ -1320,6 +1320,31 @@ INDEX_HTML = """
     modeIb: document.getElementById("modeIb"),
   };
 
+  let clickAudioCtx = null;
+
+  function playScopeClick() {
+    try {
+      if (!clickAudioCtx) {
+        clickAudioCtx = new (window.AudioContext || window.webkitAudioContext)();
+      }
+      const now = clickAudioCtx.currentTime;
+      const osc = clickAudioCtx.createOscillator();
+      const gain = clickAudioCtx.createGain();
+      osc.type = "triangle";
+      osc.frequency.setValueAtTime(1800, now);
+      osc.frequency.exponentialRampToValueAtTime(950, now + 0.025);
+      gain.gain.setValueAtTime(0.0001, now);
+      gain.gain.linearRampToValueAtTime(0.14, now + 0.0025);
+      gain.gain.exponentialRampToValueAtTime(0.0001, now + 0.04);
+      osc.connect(gain);
+      gain.connect(clickAudioCtx.destination);
+      osc.start(now);
+      osc.stop(now + 0.045);
+    } catch (_) {
+      // Ignore audio failures silently.
+    }
+  }
+
   function normalize(s) {
     return s.toLowerCase().replace(/ё/g, "е");
   }
@@ -1504,6 +1529,7 @@ INDEX_HTML = """
 
   async function switchScope(scope) {
     if (scope === state.scope) return;
+    playScopeClick();
     state.scope = scope;
     state.selectedVendors.clear();
     state.selectedCategories.clear();