chore(release): v1.4.0 with Windows FreeCAD support

[archat-hash]

This PR introduces full Windows support for the Interactive CAD Agent and bumps the project version to v1.4.0. The main focus is on improving the environment discovery mechanism and ensuring a seamless experience for Windows users.

Key Changes

• feat(cad): Expanded EnvironmentManager to support "per-user" FreeCAD installations on Windows by dynamically searching the LOCALAPPDATA directory.
• test(cad): Added comprehensive unit tests for EnvironmentManager to verify executable discovery across different platforms and environment overrides.
• chore(release): Bumped version to 1.4.0 in package.json.
• fix(cad): Improved IPC stability and path handling for Windows environments.

Technical Details

• Added path.join(process.env.LOCALAPPDATA, ...) to the candidate list in EnvironmentManager.js.
• Implemented EnvironmentManager.test.js using jest.unstable_mockModule for robust filesystem mocking.
• Verified IPC communication with FreeCAD 1.0 (Windows build).

How to Test

1. Switch to release/v1.4.0.
2. Run npm install.
3. Run npm test test/unit/EnvironmentManager.test.js to verify discovery logic.
4. (Windows only) Run node index.js cad to launch the Interactive CAD session.