Add esper:yolo skill for automated phase implementation

Context

The current workflow requires manual intervention between each plan: run /esper:build, then /esper:commit, then /esper:ship, then repeat for the next plan. For phases with many small plans, this is repetitive. YOLO mode automates the full loop — implement every pending plan in the current phase sequentially, committing at milestones, and opening the phase PR when all are done.

This is aligned with the constitution's "vibe coding toolkit for Claude Code power users" goal. It does NOT violate the "one AI, one plan, one PR at a time" principle — plans are still processed one at a time; there is just no pause between them. No multi-agent orchestration; one Claude Code session working sequentially.

The auto-commit-at-milestones approach is the key differentiator from simply calling /esper:build in a loop: YOLO commits after each logical Approach step group so the git history stays readable even for long sessions.

Existing patterns to follow:

• skills/esper-build/SKILL.md — plan selection, branch creation, activation, implementation, verification, Progress update
• skills/esper-ship/SKILL.md — archiving, pushing, phase PR logic (Step 4–7)
• All feature plans share branch feature/phase-1, so branch already exists after the first plan

Approach

1. Create skills/esper-yolo/SKILL.md with the following steps:

Step 1 — Check setup

• Verify .esper/esper.json exists; stop if not
• If there is already an active plan in .esper/plans/active/, read its title and ask: "Include it as the first plan in YOLO, or skip it and only run pending plans?"
  • Include: add it to the front of the queue (don't move it — it's already active)
  • Skip: leave it active, only run pending plans after it

Step 2 — Load phase queue

• Read all .md files in .esper/plans/pending/ where phase: matches current_phase from esper.json
• Sort by priority (ascending), then id (ascending)
• If queue is empty and no active plan is included: print "No pending plans for this phase." and stop
• Show the ordered list: #<id> — <title> (p<priority>)

Step 3 — Confirm YOLO

• Use AskUserQuestion to confirm: "YOLO mode will implement N plans automatically, committing at milestones, and open the phase PR when done. Proceed?"
• If declined: stop gracefully

Step 4 — For each plan in queue (loop)

4a. Branch

• Read branch: from plan frontmatter (all feature plans share feature/<current_phase>)
• If branch doesn't exist: git checkout -b <branch>
• If branch exists: git checkout <branch>
• If checkout fails: stop the entire YOLO run and report error

4b. Activate

• If this plan is not already active (i.e., it was pending): move from pending/ → active/, set status: active
• If already in active/ (the pre-existing active plan from Step 1): skip the move

4c. Read context

• Read the active plan file (full content), .esper/CONSTITUTION.md, and .esper/phases/<current_phase>.md

4d. Implement with milestone commits

• Follow the plan's Approach section step by step
• After each logical group of Approach steps is complete (e.g., after creating a file, after wiring up a module, after writing tests), run a milestone commit without pausing for user approval:
  Copy

  feat: <what was just implemented>
  
  Plan: #<id> — <title> (milestone)
  

• Stage only files related to the current plan's changes (git add <specific files>)
• Keep the plan file as a living document — update Approach/Files to change if something unexpected is found
• Do NOT add features beyond what the plan describes

4e. Verify

• Run verification steps from the plan's Verification section
• Run commands.test, commands.lint, commands.typecheck from esper.json (skip if empty)
• If any verification fails: STOP the entire YOLO run. Report which plan failed and what went wrong. Do NOT proceed to the next plan. The user must fix and re-run.

4f. Update Progress

• Add or update ## Progress section in the active plan file

4g. Archive

• Move plan from active/ → done/, update status: done, shipped_at: <today>
• Commit the archive:
  Copy

  chore: archive plan #<id> — <title>
  

• Stage: git add .esper/plans/done/<filename> .esper/plans/active/<filename>

4h. Continue to next plan (back to 4a)

Step 5 — Push

• After all plans are archived: git push -u origin <branch>
• If push fails: report the error; do not open PR

Step 6 — Open phase PR

• Use the same logic as esper:ship Step 7:
  • Read all plans where phase: matches current_phase
  • If any plans remain in pending/ or active/ (i.e., not all phase plans are done): print how many remain and skip PR
  • If all phase plans are in done/:
    • Collect all feature-type plans for the PR body
    • Open the phase PR targeting main with title, phase goal, shipped plans list, and acceptance criteria from the phase file
    • Print the PR URL
    • Update each feature plan's pr: field in done/ with the PR URL

Step 7 — Done

• Report: total plans shipped, PR URL (or "N plans remain, no PR opened yet")
• Suggest /esper:backlog if plans from other phases exist

Files to change

• skills/esper-yolo/SKILL.md (create — new skill implementing the steps above)

Verification

• Run: manual (install via node bin/cli.js, confirm esper-yolo appears in ~/.claude/skills/)
• Expected: skill is discoverable as /esper:yolo; on a project with 3 pending feature plans it implements them in priority order, commits at milestones, archives each, and opens the phase PR
• Edge cases:
  • No pending plans → graceful stop, clear message
  • Verification fails mid-run → stop immediately, do not proceed to next plan; leave the failed plan in active/ so the user can fix and re-run (or use /esper:continue)
  • Branch already exists (common — all phase features share a branch) → checkout, don't error
  • Mix of fix and feature plans in pending → YOLO only processes the current phase; fix-type plans with a different branch would require a branch switch; skip them and note to user (or warn and ask)
  • Active plan already exists when YOLO starts → ask user to include or skip (Step 1)

Progress

• Created skills/esper-yolo/SKILL.md with 7-step workflow: check setup → load queue → confirm → implement loop (branch, activate, read, implement+commit, verify, progress, archive) → push → phase PR → done
• Auto-commit on milestone design: stages specific files only, no git add -A, commit message format feat: ... Plan: #id — title (milestone)
• Fail-loudly on verification: stops entire run, leaves failed plan active for /esper:continue recovery
• Phase PR logic mirrors esper:ship Step 7 exactly
• Modified: skills/esper-yolo/SKILL.md (created)
• Verification: passed — node bin/cli.js shows + esper-yolo, skill installed at ~/.claude/skills/esper-yolo/SKILL.md, discoverable as /esper:yolo