[Gastown] Manual Merge Flow — Container /merge Endpoint + Review Queue Processing (P0)

[jrf0110]

Parent: #204 | Phase 1

⚠️ Critical gap: The Rig DO's startMergeInContainer() calls container.fetch('http://container/merge', ...) but the container control server has no /merge endpoint. This request 404s. The entire polecat→done→merge→closed loop is broken — beads submitted to the review queue sit there permanently.

Goal

When a polecat calls gt_done, process the review queue entry with a simple deterministic merge. No AI reasoning in Phase 1.

Current State

• agentDone() in Rig DO works: unhooks bead, submits to review queue, arms alarm ✅
• processReviewQueue() in alarm handler pops pending entries ✅
• startMergeInContainer() builds request and calls container ✅
• Container has no /merge or /git/merge endpoint ❌ — this is the gap
• Merge always fails → entry marked 'failed' → stuck

Implementation

1. Container: POST /git/merge endpoint

Add to control-server.ts:

// POST /git/merge
// Deterministic merge of a polecat branch into the target branch
{
  rigId: string,
  branch: string,        // polecat's branch (e.g., "gt/toast")
  targetBranch: string,  // e.g., "main"
  gitUrl: string         // for fetch if needed
}
→ { status: 'merged' | 'conflict', message: string, commitSha?: string }

Implementation:

1. Ensure repo is cloned/fetched for the rig
2. Create a temporary worktree on the target branch
3. git merge --no-ff <branch> in the worktree
4. If success: push to remote, clean up worktree, return merged
5. If conflict: abort merge, clean up worktree, return conflict with details
6. No AI — purely mechanical

2. Rig DO: Update startMergeInContainer()

Ensure the URL matches the container endpoint (/git/merge not /merge). Pass gitUrl from rig config.

3. Rig DO: Handle merge result

• On merged: mark review queue entry as 'merged', close the bead
• On conflict: mark entry as 'failed', create escalation bead with conflict details

Flow

1. Polecat pushes branch, calls gt_done
2. agentDone() → unhook, submit to review queue, arm alarm
3. Alarm fires → processReviewQueue() pops entry
4. startMergeInContainer() → POST /git/merge to container
5. Container merges and pushes (or reports conflict)
6. DO updates review queue entry status

Acceptance Criteria

• Container POST /git/merge endpoint implemented
• Deterministic merge (no AI) with proper git commands
• Merge success: entry marked 'merged', bead closed, branch pushed
• Merge conflict: entry marked 'failed', escalation bead created
• Rig DO startMergeInContainer() URL matches container endpoint
• End-to-end: polecat calls gt_done → review queue → merge → bead closed
• Git worktree cleanup after merge (success or failure)

[jrf0110]

Closed via PR #353. Manual merge flow implemented: container /git/merge endpoint, review queue completion callback, bead closure on merge success, escalation on conflict.