fix(fx-rt): het crackle master FX - limiter attack smooth + crossfade khi bat/tat chain

- NativeInstrumentEngine: kAttack 0.9->0.1 (het zipper khi sum nhieu track)
- app.jsx: crossfade masterFxDryGain/masterFxGain thay hard-rewire graph luc
  activation/deactivation master chain FX; worklet bao 'started' -> ramp dung
  luc; PDC tre sau khi dry silent (tranh gap 80ms)
- sf-fx-realtime.js: fade-in 512 mau luc FILL xong / resume sau underrun
- index.html + addModule: cache-buster v=202608241200
- rebuild app.precompiled.js, copy bundle vao dist/ + src-tauri/resources/
- keo dai fix cac round truoc: FILL 16, FXRT_BURST_MS, REBUFFER, pacing,
  VST GUI click/focus, solo crackle
- them harness + plans/patch scripts

native_bridge/src/FxGuiServer.cpp

@@ -239,21 +239,18 @@ bool captureHwndToJpeg(HWND hwnd, std::vector<unsigned char>& out, int quality)
     return !out.empty();
 }
 
-// --- real-input fallback ------------------------------------------------------
-// Some editors (JUCE, iZotope) reject synthetic PostMessage input entirely and
-// only react to real hardware input while their window is visible. Probe: if 2
-// consecutive clicks do not change the frame, switch this plugin to real-input
-// mode — briefly move the window topmost to the work-area corner, inject real
-// mouse events at the mapped screen position, then restore it off-screen.
-std::atomic<bool> g_realInput{false};  // plugin needs real hardware input
-// probe: hit (frame changed) resets g_miss; 2 consecutive misses switch
-// to real input. A one-off "hit" (e.g. initial settle repaint) must NOT
-// lock us onto PostMessage, so there is no permanent "detected" state.
+// --- real-input --------------------------------------------------------------
+// JUCE/iZotope editors reject synthetic PostMessage input entirely and only
+// react to real hardware input while their window is visible, so real input
+// is always on: on click the plugin window dances over the embed panel rect
+// (anchored) and real mouse events are injected at the mapped screen pos.
+// Probe-based fallback (4bb0db2 era) removed: frame-hash probing was defeated
+// by animated GUIs (meter repaint) — the frame always changes, g_miss never
+// reached 2, PostMessage stayed on and every click silently died.
+std::atomic<bool> g_realInput{true};   // always real hardware input
 std::atomic<bool> g_dance{false};      // window temporarily on-screen/topmost
 std::atomic<DWORD> g_parkUntil{0};     // safety restore deadline (GetTickCount)
 POINT g_savedCursor = {0, 0};          // cursor to restore after the dance
-int g_miss = 0;                        // consecutive no-response PostMessage clicks
-uint64_t g_preClickHash = 0;
 // Anchored mode: the frontend sends the embed panel's screen rect (physical
 // px) with every /input, so the real-input dance places the plugin window
 // exactly over the panel -- cursor never moves, no park/restore churn. Zero
@@ -261,13 +258,6 @@ uint64_t g_preClickHash = 0;
 RECT g_embedRect = {0, 0, 0, 0};
 bool g_anchored = false;              // window anchored over panel (stays until /close)
 
-uint64_t frameHash(HWND hwnd) {
-    std::vector<unsigned char> jpg;
-    if (!captureHwndToJpeg(hwnd, jpg, 70)) return 0;
-    uint64_t h = 1469598103934665603ull;  // FNV-1a 64
-    for (unsigned char b : jpg) { h ^= b; h *= 1099511628211ull; }
-    return h;
-}
 
 // Lift the window above the foreground app without making it TOPMOST (the
 // foreground-lock would otherwise swallow real clicks). Attaching to the
@@ -390,25 +380,6 @@ void relayInput(HWND hwnd, const json_object_s* o) {
     // Mouseleave reports -1,-1: finish the drag without clicking a bogus point.
     const bool outside = x < 0 || y < 0;
 
-    // Probe while still on PostMessage: a changed frame means PostMessage
-    // responds (reset miss); two consecutive no-response clicks mean the
-    // editor rejects synthetic input — switch to real hardware input.
-    if (!g_realInput) {
-        if (isDown) {
-            g_preClickHash = frameHash(hwnd);
-        } else if (isUp && g_preClickHash) {
-            Sleep(250);
-            uint64_t nowHash = frameHash(hwnd);
-            bool resp = nowHash != g_preClickHash;
-            if (resp) {
-                g_miss = 0;  // PostMessage responded — keep it
-            } else if (++g_miss >= 2) {
-                g_realInput = true;  // synthetic input rejected — go real hardware input
-                g_miss = 0;
-            }
-            g_preClickHash = 0;
-        }
-    }
 
     if (g_realInput && (isDown || isUp || type == "mousemove" || type == "wheel")) {
         if (isDown) {
@@ -583,17 +554,12 @@ void runHttpServer(HWND hwnd, std::atomic<bool>& stop) {
             if (!IsWindowVisible(hwnd))
                 SetWindowPos(hwnd, HWND_NOTOPMOST, -20000, -20000, 0, 0,
                              SWP_NOSIZE | SWP_NOACTIVATE | SWP_SHOWWINDOW);
-            if (!g_realInput) {
-                // Real-input active: the dance/anchor state is owned by the
-                // input relay — /show must not yank the window off-screen.
-                g_dance = false;
-                g_anchored = false;
-                g_parkUntil = 0;
-            }
+            // Dance/anchor state is owned by the input relay — /show must not
+            // yank the window off-screen (real input is always on).
             sendResponse(c, 200, "application/json", "{\"ok\":true}", 11);
         } else if (req.path == "/preset") {
             std::string b64;
-            fxGuiRequestCapture(hwnd, b64, 1500);
+            fxGuiRequestCapture(hwnd, b64, 500);  // 1500 blocked the HTTP worker, stalling /input (clicks)
             const std::string body = "{\"preset_b64\":\"" + b64 + "\"}";
             sendResponse(c, 200, "application/json", body.data(), (int)body.size());
         } else if (req.path == "/shm") {