Version mismatch in __init__.py

[hrco]

Found in: pre-shipment review 2026-06-30
Parent: #7
File: xbridge_mcp/__init__.py:11

__version__ = \"2.1.0\" but pyproject.toml and server.json both say 3.0.0. Breaks __version__ introspection.

[hrco]

@claude issues from pre-shipment review — please triage and assign.