fix(mastering): empty chain by default, allow removing all modules

MASTERING PANEL auto-seeded 3 modules (Dynamic EQ/Imager/Maximizer) and
removeChainModule re-added them when the chain hit zero. Chain now starts
empty everywhere (init, restore fallback, migration, graph fallback) and
can be removed down to empty; activeModule guards empty chain (null).

Cache-bust precompiled.js ?v= bump.

app/static/js/app.jsx

@@ -1330,12 +1330,6 @@ const MASTER_MODULE_IO = {
   rebalance: { input: 'rebalInput', output: 'rebalOutput' }
 };
 
-const DEFAULT_MASTER_CHAIN = [
-  { id: 'mod_eq', type: 'eq', name: 'Dynamic EQ', active: true },
-  { id: 'mod_imager', type: 'imager', name: 'Imager', active: true },
-  { id: 'mod_maximizer', type: 'maximizer', name: 'Maximizer', active: true }
-];
-
 function chainSignature(chainArray) {
   return (chainArray || []).map(m => (m.type || '') + (m.active ? '1' : '0')).join(',');
 }
@@ -1950,7 +1944,7 @@ function toggleMasteringOnMaster(activate, isBypassed) {
   if (!masterBus) return;
 
   const active = !!(activate && !isBypassed);
-  const chain = (window.currentMasteringSettings && window.currentMasteringSettings.chain) || DEFAULT_MASTER_CHAIN;
+  const chain = (window.currentMasteringSettings && window.currentMasteringSettings.chain) || [];
   const cSig = chainSignature(chain);
   // Idempotent: don't rebuild unless active state OR chain layout changed.
   if (_lastMasteringActive === active && masterBus.masteringActive === active && _lastChainSig === cSig) return;
@@ -7179,7 +7173,7 @@ const ProfileModal = ({
             } else {
               setMasteringSettings({
                 masterConnected: false,
-                activeModule: 'eq',
+                activeModule: null,
                 eqActive: true,
                 imagerActive: true,
                 maximizerActive: true,
@@ -7198,7 +7192,7 @@ const ProfileModal = ({
                 maxTransient: 25,
                 ceiling: -0.1,
                 isBypassed: false,
-                chain: DEFAULT_MASTER_CHAIN.map(m => ({ ...m })),
+                chain: [],
                 compActive: false, compThreshold: -16, compRatio: 3, compMakeup: 0,
                 limActive: false, limThreshold: -1.0,
                 excActive: false, excDrive: 40,
@@ -11610,7 +11604,7 @@ const deserializeProjectFromSchema = (schemaObj) => {
         };
     // mastering_expand.md: extension modules + dynamic chain (default = old chain order)
     if (!Array.isArray(migrated.chain)) {
-      migrated.chain = DEFAULT_MASTER_CHAIN.map(m => ({ ...m }));
+      migrated.chain = [];
     }
     if (migrated.compActive === undefined) migrated.compActive = false;
     if (migrated.compThreshold === undefined) migrated.compThreshold = -16;
@@ -13638,8 +13632,7 @@ const addMasterVst = (path) => { const fx = (masterFxList || []).find(f => f.pat
     if (removedMod && removedMod.type === 'vst3' && masterGuiOpen && masterGuiOpen.path === removedMod.path) closeMasterGui();
     setOzState(prev => {
       const removed = prev.chain.find(m => m.id === modId);
-      let chain = prev.chain.filter(m => m.id !== modId);
-      if (chain.length === 0) chain = DEFAULT_MASTER_CHAIN.map(m => ({ ...m })); // keep ≥1
+      const chain = prev.chain.filter(m => m.id !== modId);
       const flags = {};
       chain.forEach(m => { flags[chainFlag(m.type)] = !!m.active; });
       const activeModule = prev.activeModule;
@@ -13648,7 +13641,7 @@ const addMasterVst = (path) => { const fx = (masterFxList || []).find(f => f.pat
         const vi = vstFxChain.findIndex(s => s.path === removed.path);
         if (vi >= 0) vstFxChain = [...vstFxChain.slice(0, vi), ...vstFxChain.slice(vi + 1)];
       }
-      return { ...prev, chain, ...flags, vstFxChain, activeModule: chain.some(m => m.type === activeModule) ? activeModule : chain[chain.length - 1].type };
+      return { ...prev, chain, ...flags, vstFxChain, activeModule: chain.length ? (chain.some(m => m.type === activeModule) ? activeModule : chain[chain.length - 1].type) : null };
     });
   };
   const reorderChain = (fromIdx, toIdx) => {
@@ -18765,8 +18758,7 @@ const App = () => {
   };
   const [masteringSettings, setMasteringSettings] = useState({
     masterConnected: true,  // ⚠️ FIX: bật ON mặc định — MIDI item/preview PHẢI được xử lí qua mastering FX ngay khi chạy app (không cần bật/tắt power)
-    activeModule: 'eq',
-    eqActive: true,
+    activeModule: null,
     imagerActive: true,
     maximizerActive: true,
     eqLowGain: 1.5,
@@ -18784,7 +18776,7 @@ const App = () => {
     maxTransient: 25,
     ceiling: -0.1,
     isBypassed: false,
-    chain: DEFAULT_MASTER_CHAIN.map(m => ({ ...m })),
+    chain: [],
     compActive: false, compThreshold: -16, compRatio: 3, compMakeup: 0,
     limActive: false, limThreshold: -1.0,
     excActive: false, excDrive: 40,
@@ -19192,7 +19184,7 @@ const App = () => {
         } else {
           setMasteringSettings({
             masterConnected: false,
-            activeModule: 'eq',
+            activeModule: null,
             eqActive: true,
             imagerActive: true,
             maximizerActive: true,
@@ -19211,7 +19203,7 @@ const App = () => {
             maxTransient: 25,
             ceiling: -0.1,
             isBypassed: false,
-            chain: DEFAULT_MASTER_CHAIN.map(m => ({ ...m })),
+            chain: [],
             compActive: false, compThreshold: -16, compRatio: 3, compMakeup: 0,
             limActive: false, limThreshold: -1.0,
             excActive: false, excDrive: 40,

app/templates/index.html

@@ -51,7 +51,7 @@
     <script src="/static/js/services/promptTemplateManager.js?v=202607281039"></script>
     <script src="/static/js/services/undoRedoEngine.js?v=202607290941"></script>
     <script src="/static/js/services/chordTheory.js?v=202608211300"></script>
-    <script src="/static/js/app.precompiled.js?v=202608220330" defer></script>
+    <script src="/static/js/app.precompiled.js?v=202608181030" defer></script>
     <link rel="stylesheet" href="/static/css/styles.css?v=202607271016">
     <style>
         :root {