# ERD — <system or feature subset> (/docs/maintain/_templates/erd)

- **Status:** Draft
- **Last updated:** YYYY-MM-DD
- **Related ADRs:** ADR-NNNN

> Snapshot of the system as it stands today. Edit in place; never record what changed.

## Diagram [#diagram]

Draw this diagram with Archify too. In a copy, wrap the fence in
`<Diagram src="/diagrams/<project-slug>/<slug>.html" title="…">` … `</Diagram>`, with nothing else
inside: the page shows the Archify view and its Markdown the Mermaid. Outside the templates, a
bare Mermaid fence fails the build (ADR-0022).

```mermaid
erDiagram
  PROJECT ||--o{ VERSION : "has"
  PROJECT {
    text slug PK
    text visibility "public | private"
  }
  VERSION {
    text project_slug FK
    text version "semver"
  }
```

## Entities [#entities]

### `<ENTITY>` [#entity]

| Column | Type | Null | Notes |
|---|---|---|---|

**Indexes:** …
**Invariants:** rules the store or application guarantees (uniqueness, required references,
allowed values).

## Relationships [#relationships]

| From | To | Cardinality | On delete |
|---|---|---|---|

## Sensitive fields [#sensitive-fields]

Classification per [`../security/data-classification.mdx`](../security/data-classification.mdx).

| Field | Classification | Protection |
|---|---|---|