Microsoft Connectors missing after loading Knowledge Work Plugin (Google Vertex AI environment)

**Problem Description**
After installing the Knowledge Work plugin by adding the GitHub repository URL in the Plugins configuration, non-Microsoft connectors load correctly, but no Microsoft connectors (e.g., M365, Outlook, SharePoint) appear in the available connectors menu.

**Environment & Context**
- Deployment / LLM Host: Google Vertex AI
- Identity Provider for Microsoft: Microsoft Account / Azure AD (Entra ID)
- Platform: Claude Cowork / Claude Code

**Expected Behavior**
Microsoft connectors should display in the available connectors list, prompting for Microsoft OAuth/Azure AD authentication regardless of the underlying LLM provider (Google Vertex AI).

**Actual Behavior**
Microsoft connectors do not render or list as available options.

**Questions / Additional Configuration Guidance Needed**
- Does hosting via Google Vertex AI suppress Microsoft authentication endpoints by default? If so, how do I enable Microsoft connectors?
- What environment variables or Azure App Registrations (Client ID / Tenant ID) need to be configured to expose Microsoft connectors when running on Vertex AI?