feat: UI sounds, live LFO visualization, wire fix, worlds 7-12, bug fixes

- Add procedural UI sound effects (connect/disconnect, engine start/stop,
  level complete/fail, star earned, hint, navigation) via Tone.js
- Live LFO modulation visualization: knobs animate in real-time showing
  modulated value, ghost dot shows base value, number glows cyan
- Fix wire recalculation on zoom/pan/level re-entry (post-layout refresh)
- Fix retry button to keep current patch instead of reloading level
- Fix default param detection: newly added modules now populate all
  default params so level checkers work without manual param changes
- Add worlds 7-12: Secuencias y Ritmos, Texturas de Ruido, Síntesis
  Sustractiva, Espacio y Stereo, Técnicas Avanzadas, Gran Final
  (48 new levels, 144 new possible stars, 288 total stars)

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

src/engine/state.js

@@ -2,6 +2,8 @@
  * state.js — Centralized reactive state for the modular synth
  * Uses a simple pub/sub pattern for React integration
  */
+import { playConnect, playDisconnect, playModuleAdd, playModuleDelete } from './uiSounds.js';
+import { getModuleDef } from './moduleRegistry.js';
 
 let _listeners = new Set();
 let _nextModuleId = 1;
@@ -40,9 +42,15 @@ export function emit() {
 
 export function addModule(type, x, y) {
   const id = _nextModuleId++;
-  state.modules.push({ id, type, x, y, params: {}, collapsed: false });
+  // Populate ALL default params so level checkers can read them immediately
+  const def = getModuleDef(type);
+  const defaults = def
+    ? Object.fromEntries(Object.entries(def.params).map(([k, v]) => [k, v.default]))
+    : {};
+  state.modules.push({ id, type, x, y, params: defaults, collapsed: false });
   state.selectedModuleId = id;
   emit();
+  playModuleAdd();
   return id;
 }
 
@@ -53,6 +61,7 @@ export function removeModule(id) {
   );
   if (state.selectedModuleId === id) state.selectedModuleId = null;
   emit();
+  playModuleDelete();
 }
 
 export function updateModulePosition(id, x, y) {
@@ -78,19 +87,21 @@ export function addConnection(fromModuleId, fromPort, toModuleId, toPort) {
     c.to.moduleId === toModuleId && c.to.port === toPort
   );
   if (inputTaken) {
-    // Remove old connection to this input
-    removeConnection(inputTaken.id);
+    // Remove old connection to this input (silent — connect sound will play)
+    removeConnection(inputTaken.id, true);
   }
 
   const id = _nextConnectionId++;
   state.connections.push({ id, from: { moduleId: fromModuleId, port: fromPort }, to: { moduleId: toModuleId, port: toPort } });
   emit();
+  playConnect();
   return id;
 }
 
-export function removeConnection(id) {
+export function removeConnection(id, _silent = false) {
   state.connections = state.connections.filter(c => c.id !== id);
   emit();
+  if (!_silent) playDisconnect();
 }
 
 export function getModule(id) {