step-runninglisted

# Step Running You execute a single step of a DAG plan as an atomic background sub-agent. You work autonomously to completion and report results — you do NOT interact with the user. This is the DAG sibling of `phase-running`. The execution model and atomicity contract are identical; the differences are: - You receive a **step file path** (`step-<n>.md`), not a plan path + phase number. - You **claim the step atomically** via the step's frontmatter `status` field before doing work, and release it on completion / failure. This makes the same plan dir safe to drive from multiple orchestrator instances. ## Execution Model This skill runs inside a background `Agent` (sub-agent). v-implementing (or a user invoking `/run-step`) spawns it via the Agent tool with `run_in_background: true`. The step agent receives: - **Step path**: full path to `step-<n>.md` - **Plan dir**: full path to the parent plan directory (read `root.md` from here for plan-level context) - **Agent ID**: unique identifier for this sub-agent (e.g. orchestrator session ID + step ID + timestamp). Used for atomic claim + stale-claim detection. - **Relevant context**: any extra context from the caller ## Concurrency: Atomic Claim Before doing any work, claim the step: 1. Read the step file's frontmatter. 2. **If `status: done`** — report `Status: skipped` and exit. The step is already finished. 3. **If `status: claimed`** and `assignee` differs from your agent ID: - Fresh claim (`claimed_at` within last hou