test: cover BIF MCP server startup

[hummbl-dev]

Summary

• add a subprocess stdio test that initializes mcp_server.py, lists tools, and calls bif_start_session
• document BIF_SESSIONS_DIR and MCP startup/client configuration in README

Closes #8

Validation

• Not run locally; awaiting GitHub Actions.

[hummbl-dev]

REVIEW VERDICT: APPROVE at current head bf58142.

This addresses #8 directly: it adds a subprocess stdio MCP test that initializes the server, lists tools, calls bif_start_session, and verifies session persistence under BIF_SESSIONS_DIR; README now documents startup and MCP client configuration.

Verified:

• GitHub CI passes on Python 3.11 and 3.12.
• Local C:\Users\Owner\bin\python.cmd -m pytest tests/ -v passes: 96 passed.
• Local git diff --check origin/main...HEAD passes.
• Working tree remained clean after local verification.

No blocking findings. Normal peer/operator merge gate still applies.

[hummbl-dev]

REVIEW VERDICT: APPROVE

The PR directly covers #8's MCP server startup/test/documentation gap.

Verified:

• GitHub test matrix passes on Python 3.11 and 3.12.
• Local python3 -m pytest tests/ -v passes: 96 tests, including the new subprocess MCP server test.
• Local git diff --check origin/main...HEAD is clean.
• README now documents BIF_SESSIONS_DIR, python mcp_server.py, client configuration, and supported JSON-RPC methods.

No blocking findings.