feat(subscription): display next billing date and billing interval

Add current_period_end to refund eligibility checks and display next billing
date and billing interval in the subscription overview. Refactor the plan
overview layout to show subscription status more prominently.

jean.json

@@ -1,6 +1,13 @@
 {
   "scripts": {
     "setup": "cp $JEAN_ROOT_PATH/.env . && mkdir -p .claude && cp $JEAN_ROOT_PATH/.claude/settings.local.json .claude/settings.local.json",
+    "teardown": null,
     "run": "docker rm -f coolify coolify-minio-init coolify-realtime coolify-minio coolify-testing-host coolify-redis coolify-db coolify-mail coolify-vite; spin up; spin down"
-  }
-}
+  },
+  "ports": [
+    {
+      "port": 8000,
+      "label": "Coolify UI"
+    }
+  ]
+}