Add Colab CLI automation and CPU validation

[Kauandugi]

What changed

• adds a PowerShell wrapper around the official Google Colab CLI running in Ubuntu 24.04 on WSL
• makes the official notebook configurable through environment variables and gives generated cells stable IDs
• adds a T4/CUDA probe and records local Colab execution logs outside version control
• adds a deterministic Python 3.12 GitHub Actions workflow with coverage enforcement
• documents installation, OAuth, Drive mounting, smoke/full execution, cleanup, and current Colab MCP limitations

Why

This provides a reproducible path from the Windows workspace to a Colab T4 runtime while keeping statistical validation in versioned code and human approval around Google authentication.

Validation

• 29 passed, 1 skipped
• non-neural module coverage: 89.49% (minimum: 85%)
• PowerShell parser: OK
• workflow YAML parse: OK
• Ubuntu 24.04 WSL: OK
• uv 0.12.3: OK
• google-colab-cli 0.6.0: OK

The skipped test covers symbolic links, which are unavailable in the current Windows test environment and run on Linux CI.