Add Base44 to platform integrations

[Copilot]

Description

Adds Base44 as a supported platform integration alongside ManyChat, BotBuilders, OpenClaw, and Moltbook.

Type of Change

• ✨ New feature (non-breaking change which adds functionality)
• 📚 Documentation update
• 🧪 Test updates

Changes Made

• exportUtils.js: Added exportForBase44() returning a flat prediction payload (prediction_id, model_id, horizon, values, confidence, created_at, source); wired into exportPrediction() switch and module exports
• integrationsController.js: Added Base44 entry to getPlatforms() array and case 'base44' in formatPredictionForPlatform()
• README.md: Added Base44 to feature bullet, Platform Integrations section, and supported export formats
• INTEGRATIONS.md: Added Base44 as Section 5 with config example; added base44 to export formats list
• config/services.example.json: Added BASE44_API_KEY, SERVICE_BASE_URL_BASE44 (https://api.base44.com), and integration example entry

Testing

• Unit tests pass
• Integration tests pass
• Manual testing completed
• No breaking changes

New test in backend/tests/exportUtils.test.js:

test('should export for Base44 format', () => {
  const result = exportPrediction(mockPrediction, 'base44');
  expect(result).toHaveProperty('prediction_id', 'test-id');
  expect(result).toHaveProperty('source', 'ai-time-machines');
});

Screenshots (if applicable)

N/A

Checklist

• My code follows the code style of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published

Additional Context

Base44 is treated as a no-code app builder platform. The export format is intentionally flat/simple to align with typical REST ingestion APIs.