feat: add native tool extension packs

[keys-i]

Summary

Expose the native fetch and eleven-mode games executables through the shared launcher/dashboard without Bash or Python forwarding wrappers. Interactive games receive a shell-appropriate direct command, and the optional seed field reproduces randomized setup.

Closes #23

Scope

• bin/
• dev/
• lib/
• sys/
• Documentation or repository settings

Native implementation: keys-i/tools#4, commit c0942ff.

Testing

uv run --with ruff==0.16.1 ruff format --check dev/gui.py dev/run.py
uv run --with ruff==0.16.1 ruff check dev/gui.py dev/run.py
bash run.sh --self-test
uv run dev/gui.py --self-test
uv run dev/run.py --self-test
uv run --script bin/agent --self-test
bash sys/linux/clean --self-test
zsh sys/macos/clean --self-test
bash -n run.sh sys/linux/clean
zsh -n sys/macos/clean
git diff --check origin/main

macOS 26.5.2 ARM64, Python 3.14 via uv. Linux/Windows launcher behavior is covered by platform contracts and deterministic mocks. Independent fallback gatekeeper: VERDICT: PASS.

Checklist

• The change is focused and contains no unrelated files.
• The code is clean and comments explain intent or risk.
• New or changed behaviour has a repeatable test or documented manual check.
• Help text and dependencies are current.
• Destructive behaviour and elevated permissions are clearly disclosed.
• No credentials, private data, or machine-specific paths are included.

Reviewer Notes

Pack metadata resolves one validated executable from PATH and invokes it directly without a shell or implicit installer. Gameplay and argument parsing remain solely in the Rust package. keys-tools is prepared but not yet published to PyPI. Roll back commits c5a1db4 and b14e582 together.