fix(rt): restart fxRt khi chain VST doi trong luc realtime dang chay

- masteringSettings effect goi fxRtStart() khong dieu kien: early-return
  khi active + cung chainKey, stop+start lai khi chain doi (insert/remove/
  bypass/reorder VST trong MASTER FX CHAIN) — truoc day nhanh chainKey
  chet vi branch chi chay khi !fxRt.active
- test list_scan_all: path plugin phai ton tai tren dia (loc entry chet
  truoc cache); dung _scan_json helper voi file that trong tmp_path
- bump cache-bust app.precompiled.js -> 202608212300

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=202608181030" defer></script>
+    <script src="/static/js/app.precompiled.js?v=202608212300" defer></script>
     <link rel="stylesheet" href="/static/css/styles.css?v=202607271016">
     <style>
         :root {