test: Add anchor link validation to worktree verification

[michael-wojcik]

Summary

Enhance verification script to validate that anchor links in command files actually resolve.

Context

Current script validates that protocol headers exist, but doesn't verify command files use correct anchor syntax.

Proposed Implementation

1. Parse link targets in orchestrate.md, rePACT.md, comPACT.md
2. Extract anchor patterns (e.g., #setup-protocol)
3. Cross-reference against actual protocol section headers
4. Report any broken anchor links

Complexity

~20-30 lines of bash. Requires parsing markdown link syntax.

Related

• Phase E Worktree Integration (PR feat: Worktree Integration (Phase E) #144)
• verify-worktree-integration.sh Section 12