feat: VSTi autosample -> SF2/SF3 (tools/autosample_vsti.py) + bit_depth 16/24/32 render/export WAV (render_engine, plugins API, audio_editor, app.jsx encoders) + tests + task/walkthrough docs (53)

app/static/js/services/api.js

@@ -141,6 +141,12 @@ window.API_BASE_URL = window.API_BASE_URL || window.location.origin;
                 throw new Error(err.detail || 'Upload failed');
             }
             return resp.json();
+        },
+        // fetch thô có Authorization header — trả Response (dùng cho download bytes/media browse)
+        authFetch: (url, options = {}) => {
+            const headers = { ...getAuthHeaders(), ...options.headers };
+            if (options.body instanceof FormData) delete headers['Content-Type'];
+            return fetch(url, { ...options, headers });
         }
     };
 })();

app/static/js/services/fluidsynthLoader.js

@@ -6,9 +6,9 @@
 
   if (window.__FLUIDSYNTH_CDN) {
     FLUIDSYNTH_JS_URL = window.__FLUIDSYNTH_CDN;
-  } else if (window.location.hostname === 'localhost' || window.location.hostname === '127.0.0.1') {
-    FLUIDSYNTH_JS_URL = 'https://cdn.jsdelivr.net/npm/@enikey87/fluidsynth-emscripten@0.1.1/dist/libfluidsynth-2.3.0-sf3.js';
   } else {
+    // Luôn dùng WASM local — Tauri webview hostname=localhost nên CDN (jsdelivr) bị
+    // chặn làm FluidSynth không load, phải rơi về beep. File có sẵn trong source+dist.
     FLUIDSYNTH_JS_URL = '/static/js/vendor/libfluidsynth-2.3.0-sf3.js';
   }