MCP tools: virtual server configuration and audit log

[The127]

Summary

Add MCP tools for viewing/updating virtual server configuration and reading the audit log.

Depends on #232.

Tools

Tool	API Endpoint	Description
get_virtual_server	GET /{vs}	Virtual server config (name, displayName, registrationEnabled, require2fa, requireEmailVerification, signingAlgorithm)
update_virtual_server	PATCH /{vs}	Update VS config (displayName, enableRegistration, require2fa, requireEmailVerification)
list_audit_log	GET /{vs}/audit	Paginated audit log (who did what, when, allowed/denied)

Notes

• update_virtual_server must NOT expose signingAlgorithm changes — key material operations are out of scope for MCP
• Audit log is read-only and highly valuable for AI agents investigating issues
• Audit entries include: requestType, requestData, responseData, allowed, allowReasonType, userId, timestamp