docs: auto-generate llms-full.txt during build with version metadata

[dimitri-yatsenko]

Summary

Stop tracking llms-full.txt in git and auto-generate it during deployment with version metadata.

Changes

Generator Script (scripts/gen_llms_full.py)

• Added get_git_info() function to extract commit hash and branch name
• Updated header template to include timestamp, commit, and branch
• Modified generate_llms_full() to populate header with current build info

Build Process (docker-compose.yaml)

• Added python scripts/gen_llms_full.py to BUILD mode before mkdocs build
• Ensures file is generated fresh on every deployment with current git metadata

Version Control

• Added src/llms-full.txt and site/llms-full.txt to .gitignore
• Removed src/llms-full.txt from git tracking (30,871 lines deleted)

Example Output

# DataJoint Documentation (Full)

Generated: 2026-01-16 20:39:01 UTC
Commit: dc021ef
Branch: main

> DataJoint is a Python framework for building...

Benefits

1. Cleaner git history - No more 30K line diffs on doc changes
2. No merge conflicts - Generated files won't conflict across branches
3. Always fresh - File regenerates with every build
4. Traceable - Version metadata shows when/where it was generated
5. Standard practice - Follows documentation best practices

Testing

• Generator script runs successfully
• Metadata includes timestamp, commit hash, and branch
• File is properly excluded from git tracking
• Local generation produces correct output (31,555 lines)
• CI/CD build succeeds (will verify after merge)
• Deployed file accessible with metadata

Notes

• src/llms.txt (85-line index) remains committed ✓
• No changes to GitHub Actions workflow needed
• Backwards compatible - same URL, same content structure
• File will be auto-generated during next deployment