feat: implement access now crawling configuration

[nipsysdev]

Closes #17

Pull Request Summary: Access Now Crawling Configuration Implementation

Overview

This PR implements crawling configuration for Access Now (AN), adding it as a new supported source for the Ethos crawler. The implementation follows the existing pattern of source configurations and includes both listing and content extraction capabilities.

Key Changes

1. New Source Configuration: Access Now

• File: src/config/sources/an.ts
• Added complete configuration for Access Now website crawling
• Configured listing page extraction with:
  • URL: https://www.accessnow.org/news-updates/?_language=english
  • Pagination handling with 10-second delay to prevent IP blocking
  • Container selector for article items
  • Exclusion rules for press releases and guides
  • Field extraction for title, URL, date
• Configured content page extraction with:
  • Container selector for main content
  • Field extraction for title, content, and author

2. Source Integration

• File: src/config/sources/index.ts
• Added Access Now source to the main sources array
• Available as source ID "an"

3. Core Type Updates

• File: src/core/types.ts
• Extended type definitions to support the new source configuration

4. Comprehensive Testing

• Files: Multiple test files updated
• Added integration tests in src/tests/integration/an-integration.test.ts
• Added fixture data for content validation
• Updated exclusion logic testing

5. Documentation Update

• File: README.md
• Updated supported sources list to include Access Now

Technical Details

Listing Page Extraction Improvements

The implementation includes enhanced error handling and validation in the listing page extraction process:

• Better field extraction with exclusion selector support
• Improved error reporting for missing required fields
• Enhanced filtering logic with detailed reason tracking

Content Exclusion Logic

Access Now configuration includes specific exclusion rules to filter out:

• External content (identified by post-grid-item--external-icon)
• Press releases (paths containing "accessnow.org/press-release")
• Guides (paths containing "accessnow.org/guide")

Rate Limiting

Implemented a 10-second delay in pagination to prevent IP blocking by Access Now's anti-crawling mechanisms.

Test Coverage

• Added integration tests for both listing and content page crawling
• Created fixture data for content validation
• Verified successful extraction of titles, URLs, dates, and content
• Tested pagination navigation