fix: serve world-atlas topojson locally to satisfy CSP connect-src

Fetching from cdn.jsdelivr.net was blocked by connect-src 'self'.
Copy countries-110m.json from world-atlas npm package into public/geo/
and reference it as /geo/countries-110m.json instead.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

package.json

@@ -40,6 +40,7 @@
     "drizzle-kit": "^0.31.9",
     "eslint": "^9.39.2",
     "eslint-config-next": "^16.1.3",
-    "typescript": "^5.9.3"
+    "typescript": "^5.9.3",
+    "world-atlas": "^2.0.2"
   }
 }