Add RELEASE.md for framework version releases

Created comprehensive guide for releasing new framework versions (e.g., v2.0 → v2.1),
distinct from adding new UD data versions (e.g., UD 2.17 → 2.18).

**Key Sections:**

1. **Framework vs. Data Versioning**
- Clear distinction between framework versions and UD data versions
- Framework applies to all UD data branches

2. **When to Release** (Semantic Versioning)
- Major: Breaking changes (v2.0 → v3.0)
- Minor: New features (v2.0 → v2.1)
- Patch: Bug fixes (v2.0.0 → v2.0.1)

3. **Release Checklist** (12 steps)
- Update version numbers (pyproject.toml)
- Update CHANGELOG.md
- Update documentation
- Test thoroughly
- Apply to all UD data branches
- Create git tags
- Create GitHub release
- Update HuggingFace Hub
- Announce release

4. **Testing Strategy**
- Test matrix for multiple UD versions
- Schema validation
- Data integrity checks
- Backwards compatibility
- Rollback plan

5. **Common Scenarios**
- Bug fix release (patch)
- Feature release (minor)
- Breaking release (major)

6. **Best Practices**
- Semantic versioning
- Thorough testing
- Clear documentation
- Batch branch updates

7. **Troubleshooting**
- Merge conflicts
- Test failures
- Documentation sync

**Complements existing docs:**
- ADDING_NEW_UD_VERSION.md - For UD data releases
- MIGRATION.md - For user migrations
- CHANGELOG.md - For version history

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

RELEASE.md

@@ -0,0 +1,530 @@
+# Framework Release Guide
+
+This guide documents how to release a new **framework version** for the Universal Dependencies dataset (e.g., v2.0 → v2.1).
+
+**Important:** This is different from adding a new **UD data version** (e.g., UD 2.17 → 2.18). For that, see [ADDING_NEW_UD_VERSION.md](ADDING_NEW_UD_VERSION.md).
+
+## Framework vs. Data Versioning
+
+**Framework Version** (e.g., v2.0, v2.1):
+- The tooling, templates, and architecture used to generate datasets
+- Includes: generation scripts, templates, documentation, architecture decisions
+- Lives in: `tools/`, `templates/`, root documentation files
+- Applies to: All UD data versions (2.7, 2.8, ..., 2.17, 2.18, ...)
+
+**UD Data Version** (e.g., 2.17, 2.18):
+- The actual Universal Dependencies linguistic data
+- Released by the UD project ~annually
+- Each gets its own git branch
+- Can use the latest framework version
+
+**Example:** "UD 2.17 data using framework v2.0 architecture"
+
+## When to Release a New Framework Version
+
+Use [semantic versioning](https://semver.org/): `MAJOR.MINOR.PATCH`
+
+### Major Version (v2.0 → v3.0)
+
+**Breaking changes** that require user code modifications:
+
+- Schema changes (adding/removing/renaming fields)
+- Changed data format (e.g., v1.x script loader → v2.0 Parquet)
+- Incompatible API changes
+- Removing deprecated features
+
+**Example:** v1.x → v2.0 moved to Parquet format and removed Python script loader
+
+### Minor Version (v2.0 → v2.1)
+
+**New features** that are backwards compatible:
+
+- New optional fields in schema
+- New tools or scripts
+- Enhanced functionality (e.g., better MWT handling)
+- Performance improvements
+- New documentation
+
+**Example:** Adding empty_nodes field to schema while keeping all existing fields
+
+### Patch Version (v2.0.0 → v2.0.1)
+
+**Bug fixes** that don't change functionality:
+
+- Fixing parsing errors
+- Correcting metadata extraction
+- Documentation typos
+- Template rendering issues
+- Validation improvements
+
+**Example:** Fixing double-equals parsing in FEATS fields
+
+## Release Checklist
+
+### 1. Decide Version Number
+
+```bash
+# Current version
+CURRENT_VER="2.0.0"
+
+# New version (update based on changes)
+NEW_VER="2.1.0"  # or "2.0.1" for patch, "3.0.0" for major
+```
+
+**Determine type:**
+- Breaking changes? → Major
+- New features? → Minor
+- Bug fixes only? → Patch
+
+### 2. Update Version Numbers
+
+**File: pyproject.toml**
+```toml
+[project]
+name = "universal-dependencies"
+version = "2.1.0"  # Update this
+```
+
+**File: MIGRATION.md** (if major/minor)
+Update the version references in examples:
+```markdown
+# Migration Guide: v2.0 → v2.1
+
+This guide helps you migrate from v2.0 to v2.1...
+```
+
+### 3. Update CHANGELOG.md
+
+Create entry for new version:
+
+```markdown
+## [2.1.0] - 2026-01-XX
+
+### Added
+- New feature X
+- Enhanced functionality Y
+
+### Changed
+- Improved Z
+
+### Fixed
+- Bug fix for A
+
+### Removed
+- Deprecated feature B (if major version)
+```
+
+**For breaking changes (major version):**
+```markdown
+### Breaking Changes
+- **Description**: Clear explanation
+- **Impact**: Who is affected
+- **Migration**: How to update code
+```
+
+### 4. Update Documentation
+
+**Files to review and update:**
+
+- **README.md** (root) - Update version badges, examples
+- **MIGRATION.md** - Add new section if breaking changes
+- **ADDING_NEW_UD_VERSION.md** - Update if workflow changes
+- **tools/README.md** - Update if scripts change
+- **templates/README.tmpl** - Update if dataset card needs changes
+
+**Version-specific updates:**
+```bash
+# Search for old version references
+grep -r "v2\.0" --include="*.md"
+grep -r "2\.0\.0" --include="*.md"
+
+# Update as needed
+```
+
+### 5. Update Templates (if applicable)
+
+If schema or architecture changed:
+
+**File: tools/templates/README.tmpl**
+- Update schema documentation
+- Update code examples
+- Add new field descriptions
+
+**Test template rendering:**
+```bash
+cd tools
+./03_generate_README.py -o
+# Review generated README-2.17 for correctness
+```
+
+### 6. Test Changes Thoroughly
+
+**Test on sample UD version (e.g., 2.17):**
+
+```bash
+cd tools
+
+# Test metadata generation
+./02_generate_metadata.py -o
+
+# Test README generation
+./03_generate_README.py -o
+
+# Test Parquet generation (small subset)
+uv run ./04_generate_parquet.py --test
+
+# Test validation
+uv run ./05_validate_parquet.py --local --test
+```
+
+**Verify outputs:**
+- `metadata-2.17.json` has correct structure
+- `README-2.17` renders correctly
+- Parquet files load properly
+- No validation errors
+
+### 7. Update ud-hf-parquet-tools Dependency (if needed)
+
+If the framework requires a new version of the external library:
+
+**File: pyproject.toml**
+```toml
+dependencies = [
+    "ud-hf-parquet-tools>=1.2.0",  # Update minimum version
+]
+```
+
+**Update wrapper scripts:**
+```bash
+# tools/04_generate_parquet.py
+# tools/05_validate_parquet.py
+```
+
+### 8. Apply to All UD Data Branches
+
+The framework update should be applied to all active UD data branches:
+
+```bash
+# List all UD data branches
+git branch -r | grep -E "origin/[0-9]+"
+
+# Example output:
+# origin/2.7
+# origin/2.8
+# ...
+# origin/2.17
+
+# For each branch, merge the framework changes
+for branch in 2.7 2.8 2.9 2.10 2.11 2.12 2.13 2.14 2.15 2.16 2.17; do
+    echo "Updating branch ${branch}..."
+
+    git checkout ${branch}
+    git pull origin ${branch}
+
+    # Cherry-pick framework changes (or merge from main)
+    # Option A: Cherry-pick specific commits
+    git cherry-pick <commit-hash>
+
+    # Option B: Merge main (if no conflicts expected)
+    git merge main --no-edit
+
+    # Regenerate files with new framework
+    cd tools
+    ./02_generate_metadata.py -o
+    ./03_generate_README.py -o
+    cd ..
+
+    # Copy to root
+    cp tools/README-${branch} README.md
+    cp tools/metadata-${branch}.json metadata.json
+
+    # Commit
+    git add README.md metadata.json tools/
+    git commit -m "Update to framework v${NEW_VER}"
+
+    # Push
+    git push origin ${branch}
+done
+
+git checkout main
+```
+
+**Caution:** Review each branch carefully for conflicts or branch-specific issues.
+
+### 9. Create Git Tag
+
+```bash
+# Tag the main branch
+git checkout main
+git tag -a v${NEW_VER} -m "Framework release v${NEW_VER}
+
+Changes:
+- Feature A
+- Improvement B
+- Fix C
+
+See CHANGELOG.md for full details."
+
+# Push tag
+git push origin v${NEW_VER}
+```
+
+### 10. Create GitHub Release
+
+1. Go to: https://github.com/YOUR_ORG/universal_dependencies/releases/new
+2. Select tag: `v2.1.0`
+3. Release title: `Framework v2.1.0`
+4. Description:
+   ```markdown
+   ## Framework v2.1.0
+
+   This release updates the Universal Dependencies dataset **framework** to v2.1.0.
+
+   **This is a framework release, not a UD data release.** It applies to all UD data versions (2.7-2.17).
+
+   ### What's New
+
+   - Feature X: Description
+   - Enhancement Y: Description
+   - Bug fix Z: Description
+
+   ### Breaking Changes (if any)
+
+   - Change A: Migration instructions
+
+   ### Upgrade Instructions
+
+   For users: See [MIGRATION.md](MIGRATION.md) if breaking changes exist.
+
+   For maintainers: Framework has been applied to all UD data branches (2.7-2.17).
+
+   ### Full Changelog
+
+   See [CHANGELOG.md](CHANGELOG.md) for complete release notes.
+   ```
+
+5. Mark as pre-release if not stable
+6. Publish release
+
+### 11. Update HuggingFace Hub (Optional)
+
+If this is a major release that affects the dataset card or user experience:
+
+```bash
+# For each UD version branch on HF Hub
+for branch in 2.7 2.8 ... 2.17; do
+    git checkout ${branch}
+    git push hf ${branch}
+done
+```
+
+### 12. Announce Release
+
+**Update dataset card (README.md):**
+```markdown
+## What's New in Framework v2.1
+
+**Framework v2.1.0** brings the following improvements:
+- New feature X
+- Enhanced Y
+- Bug fix Z
+
+For full details, see [CHANGELOG.md](CHANGELOG.md).
+```
+
+**Announce on:**
+- HuggingFace Hub discussions
+- GitHub releases page
+- Relevant communities (if major release)
+
+## Testing Strategy
+
+### Automated Tests
+
+If tests exist in the repository:
+
+```bash
+# Run all tests
+pytest tests/
+
+# Run specific test suites
+pytest tests/test_parsing.py
+pytest tests/test_conversion.py
+```
+
+**Note:** Tests have been moved to the external `ud-hf-parquet-tools` library.
+
+### Manual Testing
+
+**Test matrix:**
+
+| UD Version | Test Type | Expected Result |
+|------------|-----------|-----------------|
+| 2.17 (latest) | Full generation | All files generated correctly |
+| 2.17 | Validation | 100% fidelity |
+| 2.17 | Load from HF | Dataset loads without errors |
+| 2.10 (mid) | Regeneration | Framework updates apply cleanly |
+| 2.7 (oldest) | Regeneration | Framework updates apply cleanly |
+
+**Specific tests:**
+
+1. **Schema validation:**
+   ```python
+   from datasets import load_dataset
+   ds = load_dataset("commul/universal_dependencies", "en_ewt", revision="2.17")
+   assert "mwt" in ds["train"].features
+   assert "empty_nodes" in ds["train"].features
+   ```
+
+2. **Data integrity:**
+   ```bash
+   uv run tools/05_validate_parquet.py --local --test
+   # Should report 0 errors
+   ```
+
+3. **Backwards compatibility (if minor/patch):**
+   ```python
+   # Old code should still work
+   ds = load_dataset("commul/universal_dependencies", "fr_gsd", revision="2.17")
+   tokens = ds["train"][0]["tokens"]
+   # No errors
+   ```
+
+### Rollback Plan
+
+If critical issues are discovered:
+
+```bash
+# Revert to previous version
+git checkout v2.0.0
+
+# Or revert specific commits
+git revert <commit-hash>
+
+# Update version back
+# Edit pyproject.toml, CHANGELOG.md
+
+# Tag rollback
+git tag -a v2.1.1 -m "Rollback v2.1.0 due to critical bug"
+git push origin v2.1.1
+```
+
+## Common Scenarios
+
+### Scenario 1: Bug Fix Release (v2.0.0 → v2.0.1)
+
+**Example:** Fix metadata parsing bug
+
+```bash
+# 1. Fix the bug in code
+# 2. Update version in pyproject.toml
+# 3. Update CHANGELOG.md
+# 4. Test on sample branch (2.17)
+# 5. Apply to all branches
+# 6. Tag and release
+```
+
+**Skip:** No migration guide needed, no schema changes
+
+### Scenario 2: Minor Feature Release (v2.0 → v2.1)
+
+**Example:** Add empty_nodes field to schema
+
+```bash
+# 1. Update templates/README.tmpl with new field docs
+# 2. Update version in pyproject.toml
+# 3. Update CHANGELOG.md
+# 4. Test on sample branch
+# 5. Apply to all branches
+# 6. Update MIGRATION.md (optional, if users need guidance)
+# 7. Tag and release
+```
+
+**Impact:** Users can optionally use new field, old code still works
+
+### Scenario 3: Major Breaking Release (v2.0 → v3.0)
+
+**Example:** Change schema significantly
+
+```bash
+# 1. Update all templates and scripts
+# 2. Update version in pyproject.toml
+# 3. Create detailed MIGRATION.md section
+# 4. Update CHANGELOG.md with breaking changes
+# 5. Test extensively on all branches
+# 6. Apply to all branches (may require regeneration)
+# 7. Tag and release
+# 8. Announce with migration guide
+```
+
+**Impact:** Users may need to update code, provide clear migration path
+
+## Version History
+
+| Version | Date | Type | Highlights |
+|---------|------|------|------------|
+| v2.0.0 | 2025-01 | Major | Parquet format, no Python script, external helpers |
+| v1.0.0 | 2024-XX | Major | Initial Python script loader |
+
+## Best Practices
+
+1. **Semantic Versioning:** Always follow semver strictly
+2. **Test Thoroughly:** Test on oldest and newest UD versions
+3. **Document Changes:** Update all relevant documentation
+4. **Communicate Clearly:** Explain impact to users
+5. **Batch Branches:** Update all UD branches together for consistency
+6. **Keep Changelog:** Maintain detailed CHANGELOG.md
+7. **Tag Consistently:** Use `v{MAJOR}.{MINOR}.{PATCH}` format
+
+## Troubleshooting
+
+### Issue: Merge conflicts when applying to branches
+
+**Solution:**
+```bash
+# If conflicts occur:
+git checkout ${branch}
+git merge main
+
+# Resolve conflicts manually
+# Prioritize branch-specific data (metadata, stats)
+# Take framework changes from main (templates, scripts)
+
+git add .
+git commit -m "Merge framework v${NEW_VER} into ${branch}"
+```
+
+### Issue: Tests fail after framework update
+
+**Solution:**
+1. Identify which test is failing
+2. Determine if it's a legitimate bug or test needs updating
+3. Fix code or update test
+4. Don't proceed with release until all tests pass
+
+### Issue: Documentation out of sync
+
+**Solution:**
+```bash
+# Systematically check all docs
+grep -r "v2\.0" --include="*.md" | grep -v CHANGELOG
+
+# Update each file
+# Commit separately for clarity
+git commit -m "Update docs to reference v2.1"
+```
+
+## Reference
+
+- **Framework documentation:** [tools/README.md](tools/README.md)
+- **UD data releases:** [ADDING_NEW_UD_VERSION.md](ADDING_NEW_UD_VERSION.md)
+- **User migration:** [MIGRATION.md](MIGRATION.md)
+- **External library:** https://github.com/bot-zen/ud-hf-parquet-tools
+- **Semantic versioning:** https://semver.org/
+
+## Support
+
+For questions about framework releases:
+- Check existing release notes in CHANGELOG.md
+- Review past release PRs/commits
+- Open an issue in the repository