fix: resolve publish workflow failures (#30)

* docs: Add CLAUDE.md with project guidelines

- Complete project structure overview
- Common commands and workflows
- Release process (always use ./scripts/release.sh)
- Architecture details and optimizations
- Linting, testing, and CI/CD guides
- Troubleshooting tips

This file provides context for Claude Code to work more effectively
with the project without repeating instructions.

* Add CHANGELOG.md for release tracking

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

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

* fix: extract version using grep instead of Python import

The publish workflow was failing because it tried to import msgspec_ext
before installing dependencies. The __init__.py imports settings.py which
requires msgspec, causing ModuleNotFoundError.

Changed to use grep to extract version directly from version.py file,
similar to how we already extract the previous version.

* fix: disable labeler workflow

The labeler workflow fails on fork PRs due to GITHUB_TOKEN permission
limitations. Added 'if: false' to disable it while keeping the
configuration for potential future use.

---------

Co-authored-by: Claude <noreply@anthropic.com>

Author: vilsonrodrigues

.github/workflows/labeler.yml

@@ -10,6 +10,8 @@ permissions:
 
 jobs:
   label:
+    # Disabled: fails on fork PRs due to token permissions
+    if: false
     runs-on: ubuntu-latest
     steps:
       - name: Checkout

.github/workflows/publish.yml

@@ -40,7 +40,7 @@ jobs:
       - name: Get current version
         id: current
         run: |
-          VERSION=$(python -c "import sys; sys.path.insert(0, 'src'); from msgspec_ext.version import __version__; print(__version__)")
+          VERSION=$(grep -oP '__version__ = "\K[^"]+' src/msgspec_ext/version.py)
           echo "version=$VERSION" >> $GITHUB_OUTPUT
           echo "Current version: $VERSION"
 
@@ -130,7 +130,7 @@ jobs:
       - name: Get version
         id: version
         run: |
-          VERSION=$(python -c "import sys; sys.path.insert(0, 'src'); from msgspec_ext.version import __version__; print(__version__)")
+          VERSION=$(grep -oP '__version__ = "\K[^"]+' src/msgspec_ext/version.py)
           echo "version=$VERSION" >> $GITHUB_OUTPUT
 
       - name: Create GitHub Release