implement-plan

# Implement Plan Execute an implementation plan file. ## Task Tracking At the start, use `TaskCreate` to create a task for each step: 1. Resolve and read the plan file 2. Read context files 3. Run `/implement` skill 4. Update plan status ## Step 1: Resolve and Read the Plan File Determine which plan file to implement using these rules in order: 1. **Explicit path** — If an absolute or relative path was passed and that file exists, use it 2. **Explicit slug** — If a slug was passed (e.g., `add-image-cache`), resolve to `.turbo/plans/<slug>.md` if that file exists 3. **Single file** — Glob `.turbo/plans/*.md`. If exactly one plan exists, use it 4. **Most recent** — If multiple plans exist, use the most recently modified 5. **Legacy fallback** — If `.turbo/plans/` does not exist but `.turbo/plan.md` exists, use it 6. **Nothing found** — If no rule above resolved to an existing file, tell the user to run `/turboplan` and stop. When a slug or path was passed but no file matched it, say which one was tried If multiple plans exist and the most-recent choice is non-obvious (e.g., several plans were modified within the same minute), use `AskUserQuestion` to let the user pick from the candidates. State the resolved plan path before continuing, then read the file. Unless an explicit path or slug was passed, confirm the resolved plan still describes work that remains to be done: - **Already implemented** — the frontmatter `status:` is `done` When the signal fires, output it a...