feat(pitch-deck): passwordless investor auth, audit logs, snapshots & PWA (#2)

Adds investor-facing access controls, persistence, and PWA support to the pitch deck:

- Passwordless magic-link auth (jose JWT + nodemailer SMTP)
- Per-investor audit logging (logins, slide views, assumption changes, chat)
- Financial model snapshot persistence (auto-save/restore per investor)
- PWA support (manifest, service worker, offline caching, branded icons)
- Safeguards: email watermark overlay, security headers, content protection,
  rate limiting, IP/new-IP detection, single active session per investor
- Admin API: invite, list investors, revoke, query audit logs
- pitch-deck service added to docker-compose.coolify.yml

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

pitch-deck/next.config.js

@@ -5,6 +5,21 @@ const nextConfig = {
   typescript: {
     ignoreBuildErrors: true,
   },
+  async headers() {
+    return [
+      {
+        source: '/:path*',
+        headers: [
+          { key: 'X-Robots-Tag', value: 'noindex, nofollow, noarchive, nosnippet' },
+          { key: 'X-Frame-Options', value: 'DENY' },
+          { key: 'X-Content-Type-Options', value: 'nosniff' },
+          { key: 'Referrer-Policy', value: 'strict-origin-when-cross-origin' },
+          { key: 'Content-Security-Policy', value: "frame-ancestors 'none'" },
+          { key: 'Permissions-Policy', value: 'camera=(), microphone=(), geolocation=()' },
+        ],
+      },
+    ]
+  },
 }
 
 module.exports = nextConfig