chore: add security headers to next.config.js

next.config.js

@@ -1,4 +1,29 @@
 /** @type {import('next').NextConfig} */
-const nextConfig = {};
+const nextConfig = {
+  // Basic hardening headers on every route. A full Content-Security-Policy
+  // is a bigger, separate effort (it would need to account for MapTiler
+  // tiles, Supabase, Vercel Analytics, and the Leaflet/OG image pipelines)
+  // and is left for a follow-up.
+  async headers() {
+    return [
+      {
+        source: "/:path*",
+        headers: [
+          { key: "X-Content-Type-Options", value: "nosniff" },
+          { key: "Referrer-Policy", value: "strict-origin-when-cross-origin" },
+          // geolocation stays enabled for this origin - the "Near me"
+          // feature genuinely uses it. Everything else this app doesn't
+          // use is disabled.
+          {
+            key: "Permissions-Policy",
+            value: "camera=(), microphone=(), geolocation=(self)",
+          },
+          // Nothing in the app needs to be iframed.
+          { key: "X-Frame-Options", value: "DENY" },
+        ],
+      },
+    ];
+  },
+};
 
 module.exports = nextConfig;