feat(05-04): calendar settings page with source management and visibility toggle

- calendar-settings-panel.tsx: source list with color dots, type badges, visibility toggle (CAL-02), edit/delete actions, connection test auto-run, delete confirmation dialog
- calendar-source-form.tsx: add/edit form with name/type/URL/credentials/color; Exchange-mode select for exchange type; username/password hidden for ICS; client-side https-only validation (T-05-14)
- settings/dashboard/calendar/page.tsx: route page rendering CalendarSettingsPanel

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/web/src/app/(portal)/settings/dashboard/calendar/page.tsx

@@ -0,0 +1,21 @@
+'use client';
+
+import { useTranslations } from 'next-intl';
+import { CalendarSettingsPanel } from '@/components/settings/calendar-settings-panel';
+
+/**
+ * Settings > Dashboard > Kalender page (D-11).
+ * Renders CalendarSettingsPanel for managing calendar sources.
+ */
+export default function CalendarSettingsPage() {
+  const t = useTranslations('settings');
+
+  return (
+    <div>
+      <h1 className="mb-6 text-lg font-semibold text-foreground">
+        {t('categoryCalendar')}
+      </h1>
+      <CalendarSettingsPanel />
+    </div>
+  );
+}