Remove macOS metadata files (._*) from repository

[Copilot]

AppleDouble format files (._*) were accidentally committed from macOS when copying files to non-native filesystems. These 5 binary metadata files in .claude/retrospectives/ served no purpose and cluttered the repository.

Changes

• Removed 5 ._* files from .claude/retrospectives/ directory tree
• Updated documentation in docs/archive/DOCUMENTATION_ORGANIZATION_REPORT.md to mark cleanup task as complete

Prevention

.gitignore already contains patterns at lines 74, 226, 252, 255 to prevent future commits:

._*
.DS_Store
**/._*
**/._.DS_Store

No code changes or functional impact. Pure cleanup.

Original prompt

Problem

The repository contains macOS metadata files (AppleDouble format files starting with ._) that were accidentally committed. These files are:

• Created automatically by macOS when copying files to non-native filesystems
• Already listed in .gitignore (lines 74, 226, 252, 255)
• Mentioned as remaining cleanup work in docs/archive/DOCUMENTATION_ORGANIZATION_REPORT.md
• Unnecessary for the repository and cause clutter

Tasks

1. Find and Remove All ._* Files

Search the entire repository for files matching the pattern ._* and remove them from Git tracking:

git ls-files | grep "^\._" 
git ls-files | grep "/\._"

Then remove each found file using:

git rm <filename>

2. Also Check for Other macOS Artifacts

Look for and remove if found:

• .DS_Store files (should already be ignored but check if any slipped through)
• ._.DS_Store files
• Any other AppleDouble format files in subdirectories

3. Verify .gitignore Coverage

Confirm that .gitignore already has these patterns (it does, but verify):

._*
.DS_Store
._.DS_Store
**/._.DS_Store
**/._*

4. Update Documentation Report

Update docs/archive/DOCUMENTATION_ORGANIZATION_REPORT.md:

• Change the "Remaining Work" section to mark the cleanup task as complete:

## Remaining Work

- [x] Clean up remaining `._` duplicate files (macOS resource forks) ✅ COMPLETED
- [ ] Complete moving any remaining root-level files
- [ ] Add missing getting-started content (quick-start.md, installation.md)
- [ ] Validate all internal links work correctly

Expected Outcome

• All ._* metadata files removed from Git history
• Repository stays clean going forward (.gitignore already handles prevention)
• Documentation updated to reflect completion
• Cleaner repository structure without macOS artifacts

Testing

After changes:

1. Run: git ls-files | grep "^\._" → should return no results
2. Run: git ls-files | grep "/\._" → should return no results
3. Verify .gitignore still contains ._* patterns
4. Confirm documentation updated

Notes

• Do NOT modify .gitignore (it's already correct)
• Only remove files from Git, don't modify any source code
• This is a cleanup task only

This pull request was created from Copilot chat.

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