Add integration tests for CapiscioMCPServer.connect() factory

[beonde]

Problem

CapiscioMCPServer.connect() is a new public entrypoint (added in PR #32) but lacks integration test coverage. Specifically, no tests verify that it:

• Correctly loads identity from environment variables
• Forwards kwargs to the underlying constructor
• Behaves predictably when called under an existing event loop
• Handles missing/invalid env vars gracefully

Unit tests cover the individual components, but the composed factory path is untested.

Proposed fix

Add integration tests in tests/test_integrations.py covering:

1. Happy path: env vars set → server created with correct identity
2. Missing env vars → clear error message
3. Kwargs forwarding (e.g., custom mode, name)

Context

Identified during PR #32 code review (Copilot review comment on mcp.py:418).