<!-- source-hash: 7663c5ccc0601f548ad7c5ca061e0918 -->
Thin wrapper around `useOgPlaceholderUrl` that resolves the correct OG placeholder URL for entity cards, allowing an explicit `placeholderUrl` prop to override the runtime-derived value.

## Key Components

### `UseEntityCardPlaceholderArgs`
Interface defining hook inputs:
- `title` — entity title used as the placeholder label
- `placeholderUrl` — explicit override; when provided (including `null`), skips runtime derivation
- `siteName` — optional site name displayed under the title
- `aspect` — output aspect ratio: `'wide'` (default, catalog cards) or `'square'` (compact chat-inline cards)

### `useEntityCardPlaceholder`
Hook that delegates URL construction to `useOgPlaceholderUrl` but applies a priority rule: an explicitly passed `placeholderUrl` (even `null`) always wins over the derived value. Only `undefined` falls through to the runtime default.

## Usage Example

```typescript
// Catalog card — derive URL from title at runtime
const placeholderSrc = useEntityCardPlaceholder({
  title: 'Microsoft 365 Business Premium',
  siteName: 'Flamingo',
  aspect: 'wide',
})

// Chat-inline card — caller pre-resolves and passes explicit URL
const placeholderSrc = useEntityCardPlaceholder({
  title: 'Entity Name',
  placeholderUrl: 'https://cdn.example.com/placeholder.png',
  aspect: 'square',
})

// Suppress placeholder entirely (e.g. real OG image already loaded)
const placeholderSrc = useEntityCardPlaceholder({
  title: 'Entity Name',
  placeholderUrl: null, // returns null; runtime default skipped
})
```

## Priority Logic

```text
placeholderUrl !== undefined  →  return placeholderUrl (string or null)
placeholderUrl === undefined  →  return derived URL from useOgPlaceholderUrl
```

**Source:** [`use-entity-card-placeholder.ts`](https://github.com/flamingo-stack/openframe-oss-lib/blob/main/use-entity-card-placeholder.ts)