docs(ocr): add endpoint consistency and repository baseline handoff

Summary

Adds the final OCR engine handoff documenting:

• endpoint and HOCR consistency fixes;
• validated runtime and regression-test evidence;
• clean master baseline and branch-protection policy;
• removal and archival of historical branches;
• recovery of pre-squash history through archive tags;
• Git workflow for future evolutions.

Validation

• Documentation-only change.
• master baseline audit completed successfully.
• Targeted regression suite: 45 passed, 2 warnings.
• No application code or runtime configuration changed.
• No Docker image rebuild required.