Replace Anthropic Claude integration with Microsoft Teams Copilot integration

[KangooGuy]

Remove the direct Anthropic Claude API integration from src/App.jsx and replace it with a Microsoft-compatible architecture.

Recommended implementation:

• Remove callClaude() direct browser fetch to https://api.anthropic.com/v1/messages
• Introduce a backend/API layer for AI requests
• Integrate with one of:
  1. Microsoft Copilot Studio
  2. Azure OpenAI Service
  3. Teams app + Bot Framework endpoint

Frontend changes:

• Rename callClaude() to something generic like generateSolutionOffer()
• Replace Anthropic-specific payload structure
• Add loading/error handling for Teams/Copilot responses
• Keep existing prompt engineering and JSON schema logic

Security improvements:

• No API keys in frontend
• Use server-side auth with Microsoft Entra ID
• Use environment variables for credentials

Expected outcome:
The tool remains accessible online for the sales team while authentication and AI generation are managed through the Microsoft ecosystem instead of direct Claude API access.