feat: Move specs and memory to git for multi-developer collaboration (v1.0.6)

BREAKING CHANGE: Specs, plans, and memory moved from .auto-build-data/ (gitignored)
to .auto-build/ (git-tracked) to enable team collaboration.

Changes:
- Specs/plans now in .auto-build/specs/ (shared with team)
- Memory (patterns, gotchas) now in .auto-build/memory/ (shared with team)
- .auto-build-data/ now only contains local data (worktrees, cache)
- Added /ab:migrate command for existing projects
- Removed symlinks from worktree-create.sh (no longer needed)

Benefits:
- Any developer can continue a plan started by another
- Patterns and gotchas shared across team
- Works on Windows/Linux/Mac without symlinks
- Full version history in git

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

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

plugin/commands/memory-save.md

@@ -101,7 +101,7 @@ For **codebase**:
 ### 5. Create Session Record
 
 Save comprehensive session record:
-`.auto-build-data/memory/sessions/{timestamp}-{feature}.json`
+`.auto-build/memory/sessions/{timestamp}-{feature}.json`
 
 ```json
 {
@@ -123,8 +123,8 @@ Save comprehensive session record:
 After saving to JSON files, convert and sync to CLAUDE.md-compatible format:
 
 1. **Load memory files**:
-   - Read `.auto-build-data/memory/patterns.json`
-   - Read `.auto-build-data/memory/gotchas.json`
+   - Read `.auto-build/memory/patterns.json`
+   - Read `.auto-build/memory/gotchas.json`
 
 2. **Convert to Markdown**:
    ```markdown