docs: add API integration plan and base client

[romain-lfg]

API Integration Plan and Base Infrastructure

Overview

This PR sets up the foundation for integrating our frontend with the backend API. It includes comprehensive documentation and base infrastructure for API integration.

Changes

• Added detailed API integration plan (docs/API_INTEGRATION.md)
• Created base API client with error handling (src/api/client.ts)
• Set up directory structure for API integration

API Integration Plan Highlights

1. Phased Approach

   • Phase 1: API Contract Definition
   • Phase 2: Environment Setup
   • Phase 3: API Integration
   • Phase 4: Testing & Validation
   • Phase 5: Monitoring & Maintenance

2. Documentation

   • Defined all required endpoints
   • Documented data schemas
   • Outlined integration testing strategy
   • Added environment configuration guide

3. Infrastructure

   • Base API client with axios
   • Error handling with custom APIError class
   • Authentication interceptors
   • TypeScript types and interfaces

Next Steps

• Review API contract with backend team
• Set up staging environment
• Begin endpoint implementation
• Create integration test suite

Testing

• Base API client is set up with proper error handling
• Documentation has been reviewed for completeness
• Directory structure follows best practices

Screenshots

N/A - Infrastructure and documentation changes only

Additional Notes

This PR serves as a foundation for our API integration. It will help the team understand what endpoints are needed and how to implement them consistently.