Fix: Remove STDOUT contamination - all logging uses STDERR (v2.0.3)

- Fixed logger.ts to write all log levels to STDERR via console.error
- Removed DEBUG console.log statements from searchApiClient.ts (lines 94, 107)
- Changed console.warn to console.error in config.ts (lines 50, 60, 61)
- Resolves JSON parsing errors in Claude Desktop while maintaining functionality

This fix ensures MCP STDIO protocol compliance: STDOUT for JSON-RPC only, STDERR for all logging.

Author: xplusplusai