Issue Workbench

Implement one actionable issue with the smallest intentional diff. $review-checkpoint owns blocker actionability; $pr-launchpad owns PR publication; Shipyard owns integration.

Inputs

• issue_number is required.
• base_branch defaults to the repository default; branch_slug is optional.
• worktree_path is optional in pull-request mode and is prepared by Shipyard in integration mode.
• max_iterations and review_base pass through to $review-checkpoint.
• handoff_mode is pull_request (default) or integration_branch.
• integration_branch and Shipyard's prepared worktree_path are required in integration mode.

Memory

Direct invocation owns issue-scoped $agent-memory; integration mode defers it to Shipyard.

Boundaries

• Default lite mode handles one issue only; do not invoke Blueprint, Shipyard, parent/child planning, or final_check.
• Stop on unclear acceptance or product behavior, unrelated dirty changes, forbidden-path changes not explicitly required, or required unrelated refactoring.
• Modify only issue-owned files. Do not touch secrets, env, generated, lock, .agents/, infrastructure, or .context/ files unless explicitly required or a verified review blocker requires it.
• .context/ may contain only local progress, review, memory, decision, and handoff artifacts. Keep progress to goal, current_step, artifacts, blockers, and validation; never commit it.
• Do not add compatibility, migration, aliases, fallbacks, dependencies, or future-proofing without an explicit requirement. Use Conventional Commits and stage only inspected paths.
• Integration children send no interim status, never push their local branches, and never run pr-launchpad.

Workflow

1. In integration mode, enter Shipyard's existing worktree_path; require its current branch to match issue-<issue_number>(-<slug>)?, require integration_branch to be its ancestor, and never create or switch the child branch. Then require a clean worktree and read the issue with:

   python3 <skill_dir>/scripts/issue_snapshot.py <issue_number>

   If truncation hides scope, rerun with larger limits. Extract requirements and constraints; do not invent behavior.

2. In pull-request mode, prepare the branch with:

   python3 <skill_dir>/scripts/start_issue_branch.py <issue_number> [--base-branch <base_branch>] [--branch-slug <branch_slug>] [--worktree-path <worktree_path>]

   review_base defaults to integration_branch in integration mode and origin/<base_branch> otherwise. Preserve any initialized five-field progress file.

3. Inspect relevant code, callers, existing patterns, and tests. Select the public behavior seam and smallest meaningful validation; do not add implementation-detail tests when no useful seam exists. Implement only the issue.

4. Inspect the complete diff and run the path guard, which includes untracked files:

   git status --short
   git diff --stat
   git diff
   python3 <skill_dir>/scripts/diff_guard.py --base <review_base>

   Use git add -N for new files. Allow a blocked path only after tracing it to an explicit issue requirement or verified review blocker. Run the smallest relevant validation, commit inspected paths, and bind its command and result to validated_head=$(git rev-parse HEAD).

5. Capture pre_review_head, then run $review-checkpoint with mode=fix_loop, review_base, and max_iterations; do not pass Shipyard's shared manifest from a child worktree. Return BLOCKED with its findings instead of treating it as PASS. Continue only after the latest completed review returns PASS with no later commit. If HEAD changed, rerun diff_guard.py and use the review fix's check evidence for the new validated_head; otherwise reuse Step 4 evidence.
6. Finish according to mode.

Handoff

In pull-request mode, after PASS, invoke nested $pr-launchpad with validated_head and its validation commands/results, then return only the PR URL.

In integration mode, pass inspected facts to the helper; it writes the canonical .context/integration-handoff.json through Shipyard's manifest interface:

# PASS
python3 <skill_dir>/scripts/integration_child.py finish --review-base <review_base> --review PASS --check "<cmd>" --known-skip "<reason>"

# defect owned by another child
python3 <skill_dir>/scripts/integration_child.py finish --review-base <review_base> --review FAIL --needs-child-fix '#123'

Return only the helper's absolute path; never reconstruct, copy, or extend its payload or choose a Shipyard child status.