chore(web-admin): track development env proxy settings

Force-add .env.development so local API proxy target is shared across clones.

Co-authored-by: Cursor <cursoragent@cursor.com>

web-admin/.env.development

@@ -0,0 +1,2 @@
+VITE_API_BASE_URL=/api
+VITE_API_PROXY_TARGET=http://127.0.0.1:8000