Flagged as worth tracking after a discussion in Slack.

## What happened

PR #30178 ("refactor(ui): remove unreachable /chat page", commit e5a3083c) deleted the `/chat` route and `src/components/chat`. That directory contained `MCPAppsPanel` and its `MCPCredentialsTab`, which was the only place in the dashboard where a user could view and disconnect/revoke their per-user MCP OAuth credentials. This reads as collateral from removing an unreachable route rather than a deliberate deprecation of credential management; the stated rationale was that the route had no sidebar entry, redirect, or backend reference

## Impact

A user can still connect an OAuth MCP server, since the connect flow in `useUserMcpOAuthFlow` and the proxy backend are intact, but there is no longer any UI to list what they have connected or to revoke a credential. The only remaining path is calling the proxy API by hand, which is not viable for non-engineer users

## The backend still supports this

The endpoints and the frontend networking helpers that backed that UI are all still present, just with no callers:

- `DELETE /v1/mcp/server/{server_id}/oauth-user-credential` - `GET /v1/mcp/server/{server_id}/oauth-use…