[otel] Update DevKit Server docs with OTEL information

[mattpodwysocki]

This PR adds Cursor and VS Code integration documentation and fixes the MCP stdio transport logging issue
that was causing JSON-RPC communication errors.

Problem

The MCP DevKit Server was outputting logs to stdout/stderr when using stdio transport, corrupting the
JSON-RPC protocol. This was caused by two issues:

1. Environment variable mismatch: Code checked MCP_DISABLE_LOGGING but scripts used
   MCP_LOGGING_DISABLE
2. OpenTelemetry diagnostic logger: OTEL's internal diagnostic logger was writing to stdout/stderr

Solution

• Fixed environment variable checking to support both MCP_DISABLE_LOGGING and MCP_LOGGING_DISABLE for
  backwards compatibility
• Suppressed OpenTelemetry diagnostic logger at module load time
• Added OTEL_LOG_LEVEL environment variable for debugging OTEL issues when needed

New Documentation

Added comprehensive integration guides for:

• Cursor IDE (docs/cursor-integration.md)
• VS Code with GitHub Copilot (docs/vscode-integration.md)

Both guides include:

• NPM, Docker, and Node setup options
• Proper stdio logging configuration (MCP_LOGGING_DISABLE=true)
• Troubleshooting sections
• Example usage prompts
• Token scope requirements

Changes

Core Fixes

• src/index.ts: Updated logging checks to support both MCP_DISABLE_LOGGING and
  MCP_LOGGING_DISABLE
• src/utils/tracing.ts: Added OTEL diagnostic logger suppression at module load time

Documentation

• docs/cursor-integration.md: New Cursor IDE integration guide
• docs/vscode-integration.md: New VS Code integration guide
• README.md: Added links to new integration docs
• .env.example: Documented OTEL_LOG_LEVEL variable
• CLAUDE.md: Added OTEL_LOG_LEVEL to environment variables section

Updated Existing Docs

• docs/claude-code-integration.md: Already had correct MCP_LOGGING_DISABLE usage
• docs/claude-desktop-integration.md: Already had correct MCP_LOGGING_DISABLE usage

Testing

Verify Stdio Transport Fix

1. Build the project:

   npm run build
   

2. Run the MCP inspector with logging disabled:
   npm run inspect:build
3. Expected: No OpenTelemetry or console logs should appear in stdio output, JSON-RPC communication
   should work cleanly
4. Verify backwards compatibility by testing both environment variables:

Test with MCP_LOGGING_DISABLE

MCP_LOGGING_DISABLE=true node dist/esm/index.js

Test with MCP_DISABLE_LOGGING

MCP_DISABLE_LOGGING=true node dist/esm/index.js

Verify New Integration Docs

1. Follow setup instructions in docs/cursor-integration.md with Cursor IDE
2. Follow setup instructions in docs/vscode-integration.md with VS Code
3. Verify server appears in respective IDE's MCP tools/servers list
4. Test a simple tool execution (e.g., "list all my Mapbox styles")

Verify OTEL Diagnostic Logging

1. With OTEL endpoint configured but logging suppressed:
   OTEL_EXPORTER_OTLP_ENDPOINT=http://localhost:4318 npm run inspect:build
2. Expected: No OTEL diagnostic output to stdio
3. Enable OTEL logging for debugging:
   OTEL_EXPORTER_OTLP_ENDPOINT=http://localhost:4318 OTEL_LOG_LEVEL=ERROR npm run inspect:build
4. Expected: OTEL errors visible (if endpoint not reachable)

Run Test Suite

npm test
Expected: All 276 tests pass ✅

Run Linter

npm run lint
Expected: No errors (only pre-existing any type warnings)

Run inspector and no errors:

Checklist

• Code has been tested locally
• Unit tests have been added or updated
• Documentation has been updated if needed

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Additional Notes