Add world settings viewing with legacy fallback

- Store map generation settings in DB when creating new worlds
- Add info button to view settings for each saved world
- Show legacy warning for worlds created before this feature

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

gsm-frontend/src/api.js

@@ -179,3 +179,9 @@ export async function getFactorioCurrentSave(token) {
     headers: { Authorization: `Bearer ${token}` },
   })
 }
+
+export async function getFactorioWorldSettings(token, saveName) {
+  return fetchAPI(`/servers/factorio/saves/${encodeURIComponent(saveName)}/settings`, {
+    headers: { Authorization: `Bearer ${token}` },
+  })
+}