feat: harden admin security, add AI trip planner, map view, and SEO/notification improvements

Security:
- requireAdmin() session check added to every admin-only server action
  (previously relied only on middleware path matching, which Next.js
  Server Actions don't reliably respect)
- Real Prisma + bcrypt admin auth, replacing hardcoded credentials; split
  into an Edge-safe auth.config.ts (used by proxy.ts) and the full
  Prisma-backed auth.ts (route handler, server actions, server components)
- Removed hardcoded fallback secret on the Instagram sync cron endpoint
- Honeypot field + per-IP rate limiting on contact/business-submission
  forms and the analytics events endpoint

Features:
- AI trip planner (/plan-olustur, /plan/[id]) backed by DeepSeek, grounded
  to only recommend isLocalApproved listings, with a deterministic
  link-injection fallback for anything the model doesn't format as markdown
- Interactive Leaflet/OpenStreetMap view on category listing pages
- Telegram notifications for new contact messages and business submissions

SEO:
- Brand-consistent favicon/apple-icon/PWA icons and default Open Graph/
  Twitter share images, generated via next/og (replacing default Next.js
  placeholders)
- BreadcrumbList structured data on category and listing detail pages
- Fixed two remaining raw <img> tags to use next/image

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

app/apple-icon.tsx

@@ -0,0 +1,27 @@
+import { ImageResponse } from 'next/og'
+import { BrandBadge } from '@/lib/ogImage'
+
+export const size = { width: 180, height: 180 }
+export const contentType = 'image/png'
+
+// iOS masks apple-touch-icon into a rounded square over a solid background —
+// unlike the browser favicon, this can't be a badge floating on transparency.
+export default function AppleIcon() {
+  return new ImageResponse(
+    (
+      <div
+        style={{
+          width: '100%',
+          height: '100%',
+          background: '#123238',
+          display: 'flex',
+          alignItems: 'center',
+          justifyContent: 'center',
+        }}
+      >
+        <BrandBadge size={140} />
+      </div>
+    ),
+    size
+  )
+}