Report the package version in the MCP client handshake

[coderyaz856]

Fixes #11

Problem

McpClientService created the MCP client with a hardcoded version: '3.1.0', so every MCP initialize request identified the CLI as 3.1.0 while the package is 3.7.0.

Change

• lib/utils/package-root.js: export PACKAGE_VERSION, read from package.json next to the existing PACKAGE_ROOT.
• lib/impl/mcp-client-service.js: use PACKAGE_VERSION for the MCP client version.
• bin/mantis.js: use the same PACKAGE_VERSION instead of reading package.json itself, so the CLI and the MCP client share one source.
• test/mcp-client-service.test.js: new test that starts a local stand-in MCP endpoint, runs listTools(), and asserts that the initialize request carries { name: 'mantisai-cli', version: <package.json version> }.

No change to commands, output, or configuration.

Testing

• node --test: 16/16 pass (15 existing + 1 new).

• The new test fails against the previous code: 3.1.0 sent, 3.7.0 expected.

• mantis --version, mantis version, and mantis --help unchanged.

• Live server (https://kellis-h200-1.csail.mit.edu), handshakes recorded through a pass-through proxy, mantis tools and mantis use get_space_context, 2 runs each:

  • before: clientInfo.version = 3.1.0 in 4 of 4 handshakes
  • after: clientInfo.version = 3.7.0 in 4 of 4 handshakes

Notes

• A full MCP session could not be completed in the live check with either version: the endpoint returned Invalid or expired MCP bearer token for developer keys that REST accepts (MCP calls reject valid developer key after successful setup #5). Behaviour was identical before and after this change.
• The bundled dist/ build was not rebuilt locally (Bun not installed); the version is resolved through the same package-root.js lookup already used for the skills directory.