[BUG] Fabric MCP not able to log in to different tenant

### Describe the bug

Fabric MCP is not able to login to a different tenant: example: client xx's tenant with 2FA setup. The Fabric MCP triggered authentication page is missing 2nd authentication where once password is provided, it won't trigger 'Authenticator' for 2 digits number prompting.

### Expected behavior

the Fabric MCP server should be able to switch tenant login to support different authentication mode smoothly. Without the need to grant read access to Azure Subscription as well. Once Fabric tenant access is granted for a given ID to enable login to Fabric portal, Fabric MCP should be able to connect with the same credentials.

### Actual behavior

this could be hallucination from github copilot.

### Reproduction Steps

Prompt used:

Fabric MCP: Connect to Fabric tenant ID = xxx, with my login email = xxxby selecting the default subscription with name = xxx . I don’t have access to the subscription but can access the tenant. The available workspace that I can access such as “Enterprise xxx”. I have access to multiple tenants. Make sure you log me to the right tenant.

### Environment

VS code - version

No source file, test, or entry point is named. Start by reproducing the Fabric MCP login with access to multiple tenants, 2FA enabled, and no Azure Subscription access; compare tenant selection and authentication behavior. Done means the intended tenant can be selected and its supported authentication flow completes without unnecessary subscription permissions.

Written by the indexing model from the issue text.