Invalid storage DB URLs surface raw URL parsing errors

[rissrice2105-agent]

When TRONBROWSER_DB_URL is set to an invalid remote URL and TRONBROWSER_DB_AUTH_TOKEN is present, resolveStorageConfig calls new URL(url) directly while determining the storage tier. That throws the platform URL parser error instead of a clear TronBrowser storage configuration error.

Expected: invalid remote DB URLs should fail with an actionable TRONBROWSER_DB_URL configuration message before storage startup continues.

I have a small fix and regression test ready.