merge-prep

You prepare the merge. You do NOT merge. You produce a merge readiness report.

Phase 1: Collect branch info

1. Read ./workspace.md for the service map (including Source Branch column)
2. Read ./plans/{feature-name}.md for the active plan
3. Check .sessions/ for the session associated with this feature
   • If a session exists, use session/{name} as the branch name
   • Use the session's source_branch as the merge target (not hardcoded main)
4. For each service with status ✅, identify the session branch name

Phase 2: Conflict detection

For each service with status ✅:

• Run git -C ../[repo] log --oneline [target]..HEAD to list commits on the feature branch
• Run git -C ../[repo] diff --name-only [target]...HEAD to list modified files
• Run git -C ../[repo] fetch origin && git -C ../[repo] merge-base --is-ancestor origin/[target] HEAD to check if up-to-date
• Cross-check: do any two branches modify the same shared files (types, configs, schemas)?
• Report potential merge conflicts

For lightweight read-only cross-checks, spawn Explore subagents (Task, Haiku).

Phase 3: PR summary generation

For each service, generate a PR summary:

### [service] — PR: session/[name] → [source_branch]

**Changes**: [N] files modified, [M] files created, [D] files deleted

**What changed**:
- [concise description of changes based on plan tasks]

**Key review points**:
- [specific areas that need human review attention]
- [any architectural decisions made during implementation]
- [constitution compliance notes]

**Tests**: [pass/fail status from QA]

**Dependencies**: [other PRs that must be merged first/after]

Phase 4: Merge order

Determine the correct merge order based on dependency waves:

1. Wave 1 services (API, data, auth) merge first
2. Wave 2 services (frontend) merge after wave 1 is on target branch
3. Wave 3 services (infra) merge last

Output

Write to ./plans/{feature-name}.md:

## Merge Prep — [DATE]

### Merge readiness
| Service | Branch | Up-to-date | Conflicts | Tests | Ready |
|---------|--------|-----------|-----------|-------|-------|
| [name] | session/[x] | ✅/❌ | none/[list] | ✅/❌ | ✅/❌ |

### Merge order
1. [service] — [branch] → [target]
2. [service] — [branch] → [target]

### PR summaries
[per-service summaries]

### Blockers
[list or "none — ready to merge"]

Ask user: "Merge prep complete. [N] services ready. Proceed with PRs?"