bridge: auto-create jBridge Qin settings (RUN_IN_EXISTING_AUXHOST 0)

Makes the unlimited-Qin fix durable: bridge writes
%APPDATA%\jBridge\SettingsFilesFor{64,32}BitPlugins\Qin_RV.jBridge
at startup when missing, so every Qin instance runs in its own
auxhost on any machine. Verified: 4 Qin ch0/1/2/9 live, 4 auxhost.exe,
0 ML_RELEASE_ERROR, GUI attachView ok=1 on all.

native_bridge/src/main.cpp

@@ -724,6 +724,48 @@ int main(int argc, char* argv[]) {
     // stderr, not stdout: stdout is reserved for machine-readable output in
     // one-shot modes (--scan JSON, --fx-gui "SF_FXGUI_PORT=...").
     std::cerr << "[NativeBridge] Starting DAW Host Bridge Engine..." << std::endl;
+
+    // JBridge per-plugin settings bootstrap: Kong Audio Qin bridges all
+    // instances through a SHARED auxhost.exe unless the per-plugin settings
+    // file disables "run in existing auxhost"; the shared auxhost then caps
+    // at 2 live instances (3rd floods ML_RELEASE_ERROR forever). Writing
+    // RUN_IN_EXISTING_AUXHOST 0 gives every instance its own auxhost ->
+    // unlimited Qin tracks. File is created if missing, never overwritten
+    // (user tweaks are respected).
+    try {
+        const char* appdata = std::getenv("APPDATA");
+        if (appdata) {
+            const char* dirs[] = {"SettingsFilesFor64BitPlugins", "SettingsFilesFor32BitPlugins"};
+            for (const char* d : dirs) {
+                std::string dir = std::string(appdata) + "\\jBridge\\" + d;
+                std::string file = dir + "\\Qin_RV.jBridge";
+                CreateDirectoryA(dir.c_str(), nullptr);
+                HANDLE h = CreateFileA(file.c_str(), GENERIC_READ, FILE_SHARE_READ, nullptr,
+                                       OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, nullptr);
+                if (h == INVALID_HANDLE_VALUE) {
+                    const char* content =
+                        "//Qin_RV.jBridge - jBridge per-plugin settings\r\n"
+                        "RUN_IN_EXISTING_AUXHOST 0\r\n"
+                        "RUN_IN_SAME_AUXHOST_GROUP 0\r\n"
+                        "AUXHOST_PRIORITY 0\r\n"
+                        "USE_SEPARATED_GUI 0\r\n"
+                        "USE_DEPRECATED_OPCODES 0\r\n";
+                    HANDLE w = CreateFileA(file.c_str(), GENERIC_WRITE, 0, nullptr,
+                                           CREATE_NEW, FILE_ATTRIBUTE_NORMAL, nullptr);
+                    if (w != INVALID_HANDLE_VALUE) {
+                        DWORD wr = 0;
+                        WriteFile(w, content, (DWORD)strlen(content), &wr, nullptr);
+                        CloseHandle(w);
+                        std::cerr << "[NativeBridge] jBridge settings created: " << file << std::endl;
+                    }
+                } else {
+                    CloseHandle(h);
+                }
+            }
+        }
+    } catch (...) {
+        std::cerr << "[NativeBridge] jBridge settings bootstrap failed (non-fatal)" << std::endl;
+    }
 #ifdef _WIN32
     // Disable Power Throttling (Efficiency Mode) for this background process
 #ifndef PROCESS_POWER_THROTTLING_IGNORE_TIMER_RESOLUTION