- fix(linux): disable modal backdrop blur on Linux (WebKitGTK/Wayland) to prevent freeze when opening Add Provider panel

- refactor(ui): add runtime platform detector and conditionally apply blur only on non-Linux platforms
- chore: verify typecheck and renderer build succeed; no functional regression expected

src/lib/platform.ts

@@ -0,0 +1,30 @@
+// 轻量平台检测，避免在 SSR 或无 navigator 的环境报错
+export const isMac = (): boolean => {
+  try {
+    const ua = navigator.userAgent || "";
+    const plat = (navigator.platform || "").toLowerCase();
+    return /mac/i.test(ua) || plat.includes("mac");
+  } catch {
+    return false;
+  }
+};
+
+export const isWindows = (): boolean => {
+  try {
+    const ua = navigator.userAgent || "";
+    return /windows|win32|win64/i.test(ua);
+  } catch {
+    return false;
+  }
+};
+
+export const isLinux = (): boolean => {
+  try {
+    const ua = navigator.userAgent || "";
+    // WebKitGTK/Chromium 在 Linux/Wayland/X11 下 UA 通常包含 Linux 或 X11
+    return /linux|x11/i.test(ua) && !/android/i.test(ua) && !isMac() && !isWindows();
+  } catch {
+    return false;
+  }
+};
+