task-decomposition

# Task Decomposition Skill

## Purpose

This skill provides expertise in decomposing specifications into executable, dependency-ordered implementation tasks. It transforms structured requirements and user stories into a concrete work plan that developers can follow sequentially or in parallel. The output is a `tasks.md` file with numbered tasks, dependency annotations, and full traceability back to the specification.

## When It Activates

The skill is triggered when the conversation involves:

- Breaking down a specification into implementation tasks
- Creating or updating a `tasks.md` file
- Discussing work breakdown, task ordering, or dependency analysis
- Planning implementation phases or sprint work
- Identifying parallelizable work streams

## Capabilities

### 1. Phase-Based Task Ordering

Tasks are organized into five sequential phases:

| Phase | Purpose | Examples |
|-------|---------|---------|
| **Setup** | Project scaffolding, tooling, configuration | Init repo, install deps, configure linter |
| **Foundation** | Core infrastructure and data layer | Database schema, base models, auth setup |
| **Stories** | Feature implementation per user story | Implement US1, US2, US3 endpoints and UI |
| **Integration** | Cross-feature wiring, E2E flows | API integration, state management, routing |
| **Finalization** | Quality assurance, polish, deployment prep | Testing, docs, CI/CD, performance tuning |

Tasks within each phase are ordered by dependency. A later phase never starts before its prerequisites in earlier phases are complete.

### 2. Task Format

Every task follows this standardized format:

```
- [ ] T001 [P] [US1] path/to/file.ts -- Description (S) [Spec FR-001]
```

Where:

- `T001` -- Unique task identifier, zero-padded and sequential
- `[P]` -- Parallelizable marker (present only if the task can run concurrently with others)
- `[US1]` -- User story reference linking to the specification
- `path/to/file.ts` -- Primary file or directory affected
- `D