implement-plan-preflight

# Implement Plan Preflight

Execute the Preflight phase of the `/itp:go` workflow. Creates ADR and Design Spec artifacts with proper cross-linking and verification.

## When to Use This Skill

- Invoked by `/itp:go` command during Preflight phase
- User asks to create an ADR for a feature
- User mentions "design spec" or "MADR format"
- Manual preflight verification needed

## Preflight Workflow Overview

```
P.1: Create Feature Branch (if -b flag)
         │
         ▼
P.2: Create ADR File (MADR 4.0)
         │
         ▼
P.3: Create Design Spec (from global plan)
         │
         ▼
P.4: Verify Checkpoint (MANDATORY)
```

**CRITICAL**: Do NOT proceed to Phase 1 implementation until ALL preflight steps are complete and verified.

---

## Quick Reference

### ADR ID Format

```
YYYY-MM-DD-slug
```

Example: `2025-12-01-clickhouse-aws-ohlcv-ingestion`

### File Locations

| Artifact    | Path                                 |
| ----------- | ------------------------------------ |
| ADR         | `/docs/adr/$ADR_ID.md`               |
| Design Spec | `/docs/design/$ADR_ID/spec.md`       |
| Global Plan | `~/.claude/plans/<adj-verb-noun>.md` |

### Cross-Links (MANDATORY)

**In ADR header**:

```markdown
**Design Spec**: [Implementation Spec](/docs/design/YYYY-MM-DD-slug/spec.md)
```

**In spec.md header**:

```markdown
**ADR**: [Feature Name ADR](/docs/adr/YYYY-MM-DD-slug.md)
```

---

## Execution Steps

### Step P.1: Create Feature Branch (Optional)

Only if `-b` flag specified. See [Workflow Steps](./references/workflow-steps.md) for details.

### Step P.2: Create ADR File

1. Create `/docs/adr/$ADR_ID.md`
2. Use template from [ADR Template](./references/adr-template.md)
3. Populate frontmatter from session context
4. Select perspectives from [Perspectives Taxonomy](./references/perspectives-taxonomy.md)
5. Use Skill tool to invoke `adr-graph-easy-architect` for diagrams

### Step P.3: Create Design Spec

1. Create folder: `mkdir -p docs/design/$ADR_ID`
2. Copy g