fix: address PR review feedback for MCP config module

- Remove committed log files from PR
- Replace fragile regex heuristic with always-compile approach
- Rename internal functions with _ prefix (private API)
- Remove cross-module _ToolMatcher import
- Add mcpServers wrapper auto-detection for Claude Desktop compat
- Simplify empty mcp_servers handling to single if block
- Add startup_timeout type validation
- Replace lambda assignments with named def statements
- Add invalid regex error handling in tool_filters parsing
- Add tests for mcpServers unwrapping, regex validation, type checks

Author: strands-agent