chore: release v4.0.0 - sync 550+ skills and restructure docs

skills/python-packaging/SKILL.md

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+---
+name: python-packaging
+description: Create distributable Python packages with proper project structure, setup.py/pyproject.toml, and publishing to PyPI. Use when packaging Python libraries, creating CLI tools, or distributing Python code.
+---
+
+# Python Packaging
+
+Comprehensive guide to creating, structuring, and distributing Python packages using modern packaging tools, pyproject.toml, and publishing to PyPI.
+
+## Use this skill when
+
+- Creating Python libraries for distribution
+- Building command-line tools with entry points
+- Publishing packages to PyPI or private repositories
+- Setting up Python project structure
+- Creating installable packages with dependencies
+- Building wheels and source distributions
+- Versioning and releasing Python packages
+- Creating namespace packages
+- Implementing package metadata and classifiers
+
+## Do not use this skill when
+
+- The task is unrelated to python packaging
+- You need a different domain or tool outside this scope
+
+## Instructions
+
+- Clarify goals, constraints, and required inputs.
+- Apply relevant best practices and validate outcomes.
+- Provide actionable steps and verification.
+- If detailed examples are required, open `resources/implementation-playbook.md`.
+
+## Resources
+
+- `resources/implementation-playbook.md` for detailed patterns and examples.