Remove hud-python from cua-agent[all] extra

hud-python is an external package that isn't published to PyPI yet,
which was blocking installation of cua-agent[all]. This change:

- Removes hud-python==0.4.52 from the [all] extra dependencies
- Keeps the separate [hud] extra for users who have access to hud-python
- Allows pip install cua-agent[all] to work without dependency errors

The hud functionality remains available as an opt-in extra via:
pip install cua-agent[hud]

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

libs/python/agent/pyproject.toml

@@ -100,8 +100,6 @@ all = [
     "python-dotenv>=1.0.1",
     # cli requirements
     "yaspin>=3.1.0",
-    # hud requirements
-    "hud-python==0.4.52",
     # gemini requirements
     "google-genai>=1.41.0",
     # qwen requirements