Meta Ads Collector

# Meta Ads Collector Skill

## Purpose
Scans the Meta Ad Library API to find active advertisements for a given brand. Extracts the number of active ads, ad formats used, ad types, and the longest-running ad duration. This collector feeds into the Marketing Audit Pipeline to populate the Paid Ads Strategy section of the final report.

## Input Schema
```typescript
// Function signature
collectMetaAds(brandName: string, domain?: string): Promise<MetaAdsData>

// brandName: The brand name to search for in the Ad Library (e.g. "Gymshark")
// domain: Optional domain to refine search (e.g. "gymshark.com"). Used to filter
// results and improve relevance when the brand name is ambiguous.
```

## Output Schema
```typescript
interface MetaAdsData {
 activeAds: number; // Total count of currently active ads
 formatsUsed: string[]; // e.g. ["image", "video", "carousel"]
 longestRunningAdDays: number; // Days the longest-running active ad has been live
 adTypes: string[]; // e.g. ["POLITICAL_AND_ISSUE_ADS", "HOUSING_ADS", "OTHER"]
 estimatedSpend?: string; // e.g. "$10,000 - $50,000" (if available from API)
 error?: string; // Present only when collector fails
}
```

## API Dependencies
- **API Name:** Meta Ad Library API
- **Endpoint:** `https://graph.facebook.com/v19.0/ads_archive`
- **Auth:** `META_ACCESS_TOKEN` environment variable (requires a Facebook App with Ad Library API access)
- **Additional env vars:** `META_APP_ID`, `META_APP_SECRET` (used for token generation if needed)
- **Cost estimate:** Free (no per-request charge)
- **Rate limits:** Subject to Meta's standard Graph API rate limits (~200 calls/hour)

## Implementation Pattern

### Data Flow
1. Receive `brandName` and optional `domain` from the pipeline
2. Call `metaAdsService.getMetaAds(brandName, domain)` which queries the Ad Library API
3. Process the returned ads array to extract metrics
4. Map processed data to the `MetaAdsData` interface

### API Query Parameters
```typescript
{
 access_token: process.env...