chore: remove obsolete files and update .gitignore

[avrabe]

Summary

• Remove obsolete CI configurations (.gitlab-ci.yml, .circleci/)
• Delete orphan documentation referencing deleted features
• Remove 270 conformance test result files that were accidentally tracked
• Update .gitignore for results directories, editor files, and build artifacts

What was removed

CI Configs

• .gitlab-ci.yml - Project uses GitHub Actions, not GitLab CI
• .circleci/ - Empty directory

Orphan Documentation

• ERROR_HARMONIZATION.md - Referenced non-existent error-harmonization-demo
• MCP_APPS_SUMMARY.md - Duplicate of docs/MCP_APPS_EXTENSION.md
• examples/PROFILING_README.md - Referenced non-existent directories
• conformance-tests/ROADMAP.md - Outdated (mentioned 15% conformance)

Build Artifacts & Test Files

• results/ - 270 conformance test result files
• security-coverage.info - Coverage build artifact
• test-config.json - Referenced deleted binaries
• test_mcp_tools.sh - Referenced deleted test-tools-server
• run-ui-server.sh - Hardcoded absolute path
• examples/flame_graph_viewer.html - Orphan HTML file

.gitignore Updates

Added entries for:

• /results/, conformance-tests/results/
• security-coverage.info, test-config.json
• .zed/ editor config
• Additional coverage file patterns

Test plan

• No code changes, only file deletions
• Pre-commit hooks pass
• CI passes