fix(ui): keep main window closable after a native dialog on Windows (#6319)

A native Windows MessageBox attached to a parent window disables that
window (WS_DISABLED) for its lifetime and re-enables it on dismissal.
When the parent is the main window — whose WindowClosing hook hides
instead of closes — the enable/hide sequence races and leaves the window
unable to process its close (X) button afterwards, so e.g. a rejected
login error dialog left the main window stuck open.

Route all native dialogs through src/lib/dialogs.ts, which forces
Detached: true on Windows (NULL owner, no window ever disabled) and is a
no-op on macOS/Linux (keeps the attached sheet-style presentation).

client/ui/frontend/src/modules/main/MainConnectionStatusSwitch.tsx

@@ -1,8 +1,9 @@
 import { useCallback, useEffect, useMemo, useRef, useState } from "react";
 import { useTranslation } from "react-i18next";
-import { Dialogs, Events } from "@wailsio/runtime";
+import { Events } from "@wailsio/runtime";
 import { Connection, WindowManager } from "@bindings/services";
 import i18next from "@/lib/i18n";
+import { errorDialog } from "@/lib/dialogs.ts";
 import { ToggleSwitch } from "@/components/switches/ToggleSwitch.tsx";
 import { useStatus } from "@/contexts/StatusContext.tsx";
 import { useProfile } from "@/contexts/ProfileContext.tsx";
@@ -105,7 +106,7 @@ async function startLogin(): Promise<void> {
     } catch (e) {
         WindowManager.CloseBrowserLogin().catch(console.error);
         if (cancelled) return;
-        await Dialogs.Error({
+        await errorDialog({
             Title: i18next.t("connect.error.loginTitle"),
             Message: errorMessage(e),
         });
@@ -192,7 +193,7 @@ export const MainConnectionStatusSwitch = () => {
         } catch (e) {
             setAction(null);
             await refresh();
-            await Dialogs.Error({
+            await errorDialog({
                 Title: t("connect.error.connectTitle"),
                 Message: errorMessage(e),
             });
@@ -212,7 +213,7 @@ export const MainConnectionStatusSwitch = () => {
         } catch (e) {
             setAction(null);
             await refresh();
-            await Dialogs.Error({
+            await errorDialog({
                 Title: t("connect.error.disconnectTitle"),
                 Message: errorMessage(e),
             });