Implement Worker

Single-task mini-orchestrator. Receives a task ID, spawns a code-only sub-worker.

Step 1: Load Task

TaskGet(<task-id>) — capture description and metadata.

Pre-computed context (set by develop): if metadata.breadcrumb and metadata.epic_design exist, use them directly — skip ancestor walk.

Fallback (invoked outside develop): if metadata.parent_id exists, walk ancestor chain to epic root:

1. Repeatedly TaskGet(parent_id) until no parent_id
2. Build breadcrumb root-first, excluding current task: "Epic > Phase > ..."
3. Source metadata.design from root epic

Step 1.5: Complexity Assessment

Decompose if ALL hold:

• 4+ files touching unrelated components, OR 3+ concerns needing different test context
• task.metadata.depth is set AND < 3 (depth cap prevents unbounded nesting)

depth absent → assume leaf, do NOT decompose (prevents unbounded recursion).

Threshold met → Step 1.6. Otherwise → Step 2.

Step 1.6: Decompose Path

Skip Steps 2–6. Decompose, dispatch children, verify.

1. Create children — one per concern. Each: metadata: {parent_id: task.id, depth: (task.metadata.depth ?? 0) + 1, ...inherited}.
2. Dispatch — up to 4 concurrent Task(subagent_type="general-purpose") using Sub-Worker Prompt (Step 2). Each child's breadcrumb = parent breadcrumb + current task subject.
3. Verify children — after all agents return, TaskGet each child. Any child still in_progress → report which completed and which failed, do NOT proceed to acceptance or mark parent complete.
4. All children completed → Skill("acceptance", args=task.id) — PASS → complete task. FAIL → report, do not complete.

Step 2: Claim Task

TaskUpdate(taskId, status: "in_progress", owner: "solo") — establish ownership before dispatching any work.

Step 3: Sub-Worker Prompt

Spawn Task(subagent_type="general-purpose"). Trivial tasks (single-file, <20 lines changed, no new logic — e.g. rename, config tweak): use model="sonnet" to save cost.

Implement task <task-id>.

## Task
<description from TaskGet>

## Ancestry
<breadcrumb from Step 1; omit if no parent>

## Epic Context
<root epic subject + metadata.design summary; omit if no parent>

## Protocol
1. Read every file in scope + 2-3 nearby test files to learn conventions.
   TDD: failing test → red → implement → green. No test infra → note, implement directly.
2. Build + test. Same root error 2x → stop + report. 3 distinct errors → report all, stop.
3. Self-check: re-read changed files. Remove debug artifacts, low-value comments, unused imports. Flatten nesting via early returns. Apply language-idiomatic patterns.

## Rules
- TDD first. Standards: rules/test-quality.md
- Never run git commands or Skill("commit")
- Only modify files in task scope
- Bug elsewhere → TaskCreate(subject: "Found: ...", metadata: {type: "bug", priority: "P2", project: "<repo root>"})

Step 3.5: Verify Sub-Worker

TaskGet(<task-id>) after sub-worker returns. If status is still in_progress (worker crashed or failed to complete), return failure to caller — do NOT proceed to Step 4.

Step 4: Complete Task

Only if Step 3.5 confirms no failure. TaskUpdate(taskId, status: "completed", metadata: {completedAt: "<ISO 8601>"}) — mark complete here, not inside sub-worker.

Step 5: Return

Completion summary (files changed, what implemented). No staging, no commit — caller handles.