Add provider and connection details configuration page to UI

[manojbajaj95]

Summary

Add a provider and connection details/configuration page to the top-level Next.js UI under ui/.

Basic requirements

• Show provider details such as display name, auth type, source, API URL, docs URL, configured scopes, and OAuth/DCR/API-key/browser configuration metadata.
• Show connection details for the selected provider, including connection name, default status, auth type, status, scopes, base/API URL, and expiry.
• Link existing provider cards and connection rows to this detail/configuration view.
• Keep secrets redacted; expose only safe configuration state and metadata.

Notes

The current UI is the top-level Next.js app in ui/, with provider and connection data already loaded from /api/connections.