feat: improve Claude Desktop support and token refresh reliability

[rathga]

I tried using this in Claude Desktop, but had a few issues. I asked Claude code to fix them, which it did and it's all working smoothly now. Here's a PR with the changes that it came up with.

Summary

• Fix dotenv path resolution: Resolve .env relative to script location instead of process.cwd(), which differs when launched by Claude Desktop (often C:\Windows\System32)
• Improve token refresh: Add proactive refresh on token expiration, 401 retry logic, and use TENANT_ID from env for the refresh endpoint instead of hardcoding /consumers/
• Fix token file resolution in CLI: Look for tokens.json next to the script before falling back to cwd, so it works when launched from any directory
• Pass expiresAt through CLI: Forward token expiration time from tokens.json to the server so it can proactively refresh before API calls fail
• Update README: Add Claude Desktop configuration instructions, token refresh documentation, and troubleshooting for common issues (server exit on Windows, 401 errors with personal accounts, tenant ID configuration)
• Remove verbose logging: Clean up request/response debug logging that leaked into production

Test plan

• Verify MCP server starts correctly from Claude Desktop on Windows using build/cli.js
• Verify automatic token refresh works when access token expires (~1 hour)
• Verify 401 retry logic recovers from expired tokens mid-session
• Verify .env is loaded correctly regardless of working directory
• Verify tokens.json is found when server is launched from a different directory
• Run npm run build to confirm TypeScript compiles without errors

🤖 Generated with Claude Code