fix: harden proxy auth and SSRF defenses

components/layout/navigation-rail.tsx

@@ -17,6 +17,7 @@ import { useSettingsStore } from "@/stores/settings-store";
 import { usePolicyStore } from "@/stores/policy-store";
 import { useAuthStore } from "@/stores/auth-store";
 import { useAccountStore } from "@/stores/account-store";
+import { getActiveAccountSlotHeaders } from "@/lib/auth/active-account-slot";
 import { getInitials } from "@/lib/account-utils";
 import { cn, formatFileSize } from "@/lib/utils";
 import { PluginSlot } from "@/components/plugins/plugin-slot";
@@ -219,13 +220,8 @@ export function NavigationRail({
 
   useEffect(() => {
     let cancelled = false;
-    const { client } = useAuthStore.getState();
-    if (!client) return;
-    const headers: Record<string, string> = {
-      'Authorization': client.getAuthHeader(),
-      'X-JMAP-Server-URL': client.getServerUrl(),
-      'X-JMAP-Username': client.getUsername(),
-    };
+    const headers = getActiveAccountSlotHeaders();
+    if (!headers['X-JMAP-Cookie-Slot']) return;
     fetch('/api/admin/stalwart-check', { headers })
       .then(res => res.json())
       .then(data => {

components/settings/calendar-management-settings.tsx

@@ -4,6 +4,7 @@ import { useState, useRef, useEffect } from 'react';
 import { useTranslations } from 'next-intl';
 import { useCalendarStore } from '@/stores/calendar-store';
 import { useAuthStore } from '@/stores/auth-store';
+import { getActiveAccountSlotHeaders } from '@/lib/auth/active-account-slot';
 import { toast } from '@/stores/toast-store';
 import { SettingsSection } from './settings-section';
 import { Plus, Pencil, Trash2, Calendar as CalendarIcon, Copy, Link, Upload, Globe, RefreshCw, Eraser } from 'lucide-react';
@@ -203,7 +204,10 @@ export function CalendarManagementSettings() {
 
     fetch('/api/caldav/discover', {
       method: 'POST',
-      headers: { 'Content-Type': 'application/json' },
+      headers: {
+        'Content-Type': 'application/json',
+        ...getActiveAccountSlotHeaders(),
+      },
       body: JSON.stringify({
         accounts: Array.from(accounts.entries()).map(([key, candidates]) => ({ key, candidates })),
       }),