v0.1.11: Install from uv.lock in image build to pin dependencies (#28)

`uv tool install .` re-resolved dependencies from pyproject.toml's loose
constraints on every build, so a rebuild silently pulled mcp 2.x — which
dropped mcp.server.fastmcp — and the stdio server crashed on import,
breaking the claude.ai connection.

Switch to `uv sync --frozen` so the image installs the exact locked
versions and the build fails on a stale lock instead of re-resolving.
uv tool install has no way to consume uv.lock; sync uses a project venv,
so put /app/.venv/bin on PATH for the entry point.