Add branding format support to JS and Python SDKs

Summary

This PR adds type definitions for the branding format to both the JavaScript/TypeScript and Python SDKs. The branding format is already implemented and supported in the API but was missing from the SDK type definitions.

Changes:

• Added 'branding' to the FormatString type union in both SDKs
• Created BrandingProfile interface/class with comprehensive type definitions including:
  • Color schemes (light/dark), colors, fonts, typography
  • Spacing, components (buttons, inputs), icons, images
  • Layout, animations, tone, personality
• Added branding?: BrandingProfile field to the Document type in both SDKs

The types were copied from the API's existing apps/api/src/types/branding.ts to ensure compatibility.

Review & Testing Checklist for Human

• End-to-end test with JS SDK: Test scraping with formats: ["branding"] and verify the returned branding data is properly typed and matches the BrandingProfile interface
• End-to-end test with Python SDK: Test scraping with formats: ["branding"] and verify the returned branding data is properly typed and matches the BrandingProfile class
• Verify type completeness: Check that the BrandingProfile types match what the API actually returns in production (the API tests for branding are currently skipped, which may indicate special setup requirements or instability)

Test Plan

// JS SDK test
const client = new Firecrawl({ apiKey: 'fc-...' });
const result = await client.scrape('https://firecrawl.dev', { 
  formats: ['branding'] 
});
console.log(result.branding); // Should be typed as BrandingProfile

# Python SDK test
from firecrawl import Firecrawl
client = Firecrawl(api_key='fc-...')
result = client.scrape('https://firecrawl.dev', formats=['branding'])
print(result.branding)  # Should be typed as BrandingProfile

Notes

• The JS SDK build passes successfully with no new errors
• The Python SDK uses more generic Dict[str, Any] types for nested structures compared to TypeScript's more specific types, which is acceptable for Python's dynamic nature
• The API implementation already exists in apps/api/src/lib/branding/ with comprehensive branding extraction logic

Link to Devin run: https://app.devin.ai/sessions/24af7e0ad2d64415966c1abf54522ada
Requested by: abi@sideguide.dev (@abimaelmartell)

Summary by cubic

Adds branding format support to the JS and Python SDKs, aligned with the API’s existing branding schema. Request ["branding"] to get typed data via Document.branding; Python normalizes colorScheme to color_scheme.

• New Features

  • Added "branding" to FormatString in both SDKs.
  • Introduced BrandingProfile type/class (colors, fonts, typography, spacing, components, icons, images, animations, layout, tone, personality).
  • Added Document.branding in both SDKs.

• Bug Fixes

  • Python: normalize branding.colorScheme -> color_scheme for consistent snake_case.

^{Written for commit 558a1eb. Summary will update automatically on new commits.}