feat: Add automatic email signature

src/App.tsx

@@ -54,6 +54,7 @@ const AdminUsers = lazy(() => import("./pages/AdminUsers"));
 const AdminBlog = lazy(() => import("./pages/AdminBlog"));
 const AdminSettings = lazy(() => import("./pages/AdminSettings"));
 const AdminContact = lazy(() => import("./pages/admin/AdminContact"));
+const AdminEmailSettings = lazy(() => import("./pages/admin/AdminEmailSettings"));
 
 // User routes (lazy-loaded)
 const Profile = lazy(() => import("./pages/Profile"));
@@ -136,6 +137,7 @@ function AppContent() {
                 <Route path="/admin/blog" element={<AdminBlog />} />
                 <Route path="/admin/settings" element={<AdminSettings />} />
                 <Route path="/admin/contact" element={<AdminContact />} />
+                <Route path="/admin/email-settings" element={<AdminEmailSettings />} />
                 
                 {/* Utility routes - lazy loaded */}
                 <Route path="/force-logout" element={<ForceLogout />} />

src/components/layout/AdminSidebar.tsx

@@ -1,4 +1,4 @@
-import { LayoutDashboard, FileText, Flag, Users, Settings, ArrowLeft, ScrollText, BookOpen, Inbox } from 'lucide-react';
+import { LayoutDashboard, FileText, Flag, Users, Settings, ArrowLeft, ScrollText, BookOpen, Inbox, Mail } from 'lucide-react';
 import { NavLink } from 'react-router-dom';
 import { useUserRole } from '@/hooks/useUserRole';
 import { useSidebar } from '@/hooks/useSidebar';
@@ -62,6 +62,10 @@ export function AdminSidebar() {
       title: 'Settings',
       url: '/admin/settings',
       icon: Settings,
+    }, {
+      title: 'Email Settings',
+      url: '/admin/email-settings',
+      icon: Mail,
     }] : []),
   ];
 

src/pages/admin/AdminEmailSettings.tsx

@@ -0,0 +1,201 @@
+import { useState, useEffect } from 'react';
+import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query';
+import { Save, Loader2, Mail } from 'lucide-react';
+import { supabase } from '@/integrations/supabase/client';
+import { Button } from '@/components/ui/button';
+import { Textarea } from '@/components/ui/textarea';
+import { Label } from '@/components/ui/label';
+import {
+  Card,
+  CardContent,
+  CardDescription,
+  CardHeader,
+  CardTitle,
+} from '@/components/ui/card';
+import { AdminLayout } from '@/components/layout/AdminLayout';
+import { useUserRole } from '@/hooks/useUserRole';
+import { handleError, handleSuccess } from '@/lib/errorHandler';
+import { Alert, AlertDescription } from '@/components/ui/alert';
+
+export default function AdminEmailSettings() {
+  const queryClient = useQueryClient();
+  const { isSuperuser, loading: rolesLoading } = useUserRole();
+  const [signature, setSignature] = useState('');
+
+  // Fetch email signature
+  const { data: signatureSetting, isLoading } = useQuery({
+    queryKey: ['admin-email-signature'],
+    queryFn: async () => {
+      const { data, error } = await supabase
+        .from('admin_settings')
+        .select('setting_value')
+        .eq('setting_key', 'email.signature')
+        .single();
+
+      if (error && error.code !== 'PGRST116') { // PGRST116 = no rows returned
+        throw error;
+      }
+
+      // Type guard for the setting value
+      const settingValue = data?.setting_value as { signature?: string } | null;
+      return settingValue?.signature || '';
+    },
+  });
+
+  useEffect(() => {
+    if (signatureSetting !== undefined) {
+      setSignature(signatureSetting);
+    }
+  }, [signatureSetting]);
+
+  // Update email signature mutation
+  const updateSignatureMutation = useMutation({
+    mutationFn: async (newSignature: string) => {
+      const { data: existing } = await supabase
+        .from('admin_settings')
+        .select('id')
+        .eq('setting_key', 'email.signature')
+        .single();
+
+      if (existing) {
+        // Update existing
+        const { error } = await supabase
+          .from('admin_settings')
+          .update({
+            setting_value: { signature: newSignature },
+            updated_at: new Date().toISOString(),
+          })
+          .eq('setting_key', 'email.signature');
+
+        if (error) throw error;
+      } else {
+        // Insert new
+        const { error } = await supabase
+          .from('admin_settings')
+          .insert({
+            setting_key: 'email.signature',
+            setting_value: { signature: newSignature },
+            category: 'email',
+            description: 'Email signature automatically appended to all contact submission replies',
+          });
+
+        if (error) throw error;
+      }
+    },
+    onSuccess: () => {
+      queryClient.invalidateQueries({ queryKey: ['admin-email-signature'] });
+      handleSuccess('Saved', 'Email signature has been updated successfully');
+    },
+    onError: (error) => {
+      handleError(error, { action: 'update_email_signature' });
+    },
+  });
+
+  const handleSave = () => {
+    updateSignatureMutation.mutate(signature);
+  };
+
+  // Show loading state while roles are being fetched
+  if (rolesLoading) {
+    return (
+      <div className="flex items-center justify-center min-h-screen">
+        <Loader2 className="h-8 w-8 animate-spin text-muted-foreground" />
+      </div>
+    );
+  }
+
+  // Superuser-only access check
+  if (!isSuperuser()) {
+    return (
+      <AdminLayout>
+        <div className="flex items-center justify-center min-h-[60vh]">
+          <Card className="max-w-md">
+            <CardContent className="pt-6 text-center">
+              <Mail className="h-12 w-12 text-destructive mx-auto mb-4" />
+              <h2 className="text-xl font-semibold mb-2">Access Denied</h2>
+              <p className="text-muted-foreground">
+                Email settings can only be managed by superusers.
+              </p>
+            </CardContent>
+          </Card>
+        </div>
+      </AdminLayout>
+    );
+  }
+
+  return (
+    <AdminLayout>
+      <div className="mb-8">
+        <h1 className="text-4xl font-bold mb-2">Email Settings</h1>
+        <p className="text-muted-foreground">
+          Configure automatic email signature for contact submission replies
+        </p>
+      </div>
+
+      <Card>
+        <CardHeader>
+          <CardTitle className="flex items-center gap-2">
+            <Mail className="h-5 w-5" />
+            Email Signature
+          </CardTitle>
+          <CardDescription>
+            This signature will be automatically appended to all email replies sent to users from the Contact Submissions page.
+            The signature will be added after a separator line.
+          </CardDescription>
+        </CardHeader>
+        <CardContent className="space-y-4">
+          <Alert>
+            <AlertDescription>
+              <strong>Preview:</strong> The signature will appear as:
+              <div className="mt-2 p-3 bg-muted rounded-md text-sm font-mono">
+                [Your reply message]
+                <br />
+                <br />
+                ---
+                <br />
+                {signature || '[No signature set]'}
+              </div>
+            </AlertDescription>
+          </Alert>
+
+          <div className="space-y-2">
+            <Label htmlFor="signature">Signature Text</Label>
+            <Textarea
+              id="signature"
+              value={signature}
+              onChange={(e) => setSignature(e.target.value)}
+              placeholder="Best regards,&#10;The ThrillWiki Team&#10;&#10;Need help? Reply to this email or visit https://thrillwiki.com/contact"
+              rows={8}
+              disabled={isLoading}
+            />
+            <p className="text-xs text-muted-foreground">
+              Use plain text. Line breaks will be preserved. You can include team name, contact info, or helpful links.
+            </p>
+          </div>
+
+          <div className="flex items-center gap-3 pt-4">
+            <Button
+              onClick={handleSave}
+              disabled={updateSignatureMutation.isPending || isLoading}
+            >
+              {updateSignatureMutation.isPending && (
+                <Loader2 className="mr-2 h-4 w-4 animate-spin" />
+              )}
+              <Save className="mr-2 h-4 w-4" />
+              Save Signature
+            </Button>
+            {signature !== signatureSetting && (
+              <Button
+                variant="outline"
+                onClick={() => setSignature(signatureSetting || '')}
+                disabled={updateSignatureMutation.isPending}
+              >
+                Reset Changes
+              </Button>
+            )}
+          </div>
+        </CardContent>
+      </Card>
+    </AdminLayout>
+  );
+}

supabase/functions/send-admin-email-reply/index.ts

@@ -78,6 +78,20 @@ const handler = async (req: Request): Promise<Response> => {
       return createErrorResponse({ message: 'Submission not found' }, 404, corsHeaders);
     }
 
+    // Fetch email signature from admin settings
+    const { data: signatureSetting } = await supabase
+      .from('admin_settings')
+      .select('setting_value')
+      .eq('setting_key', 'email.signature')
+      .single();
+
+    const emailSignature = signatureSetting?.setting_value?.signature || '';
+    
+    // Append signature to reply body if it exists
+    const finalReplyBody = emailSignature 
+      ? `${replyBody}\n\n---\n${emailSignature}`
+      : replyBody;
+
     // Rate limiting: max 10 replies per hour
     const oneHourAgo = new Date(Date.now() - 60 * 60 * 1000).toISOString();
     const { count } = await supabase
@@ -124,7 +138,7 @@ const handler = async (req: Request): Promise<Response> => {
         from: 'ThrillWiki Admin <admin@thrillwiki.com>',
         to: `${submission.name} <${submission.email}>`,
         subject: finalSubject,
-        text: replyBody,
+        text: finalReplyBody,
         headers: {
           'Message-ID': messageId,
           'In-Reply-To': inReplyTo,
@@ -156,7 +170,7 @@ const handler = async (req: Request): Promise<Response> => {
         from_email: 'admin@thrillwiki.com',
         to_email: submission.email,
         subject: finalSubject,
-        body_text: replyBody,
+        body_text: finalReplyBody,
         direction: 'outbound',
         sent_by: user.id,
         metadata: {