Clean up root directory: remove temporary files and backup artifacts

[Copilot]

Root Directory Cleanup Plan

• Remove temporary test/analysis markdown files
  • Delete SERENA_TEST_RESULTS.md
  • Delete SERENA_TEST_ANALYSIS.md
  • Delete BRANCH_STATUS.md
  • Delete SUMMARY.md
  • Delete VERIFICATION_PROOF.md
• Remove duplicate/misplaced documentation
  • Delete HTTP_MCP_SERVERS.md (content exists in docs/)
  • Delete mcp-gateway.md (W3C spec format belongs in docs/)
• Remove backup files and directories
  • Delete bak/ directory (contained go.mod and go.sum backups)
  • Delete go.mod.bak
• Verify essential files remain
  • Keep README.md
  • Keep CONTRIBUTING.md
  • Keep SECURITY.md
  • Keep AGENTS.md
• Run final verification
  • Build and test the project
  • Verify no broken references
• Fix linting errors
  • Fix gofmt formatting in internal/difc/agent_test.go

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[lpcox]

@copilot please fix these linting errors
make lint
shell: /usr/bin/bash -e {0}
env:
GOTOOLCHAIN: local
Running linters...
Running gofmt check...
The following files are not formatted:
internal/difc/agent_test.go
make: *** [Makefile:26: lint] Error 1

[Copilot]

@copilot please fix these linting errors
make lint
shell: /usr/bin/bash -e {0}
...

Fixed in e7be697. The struct fields in test cases are now properly aligned according to gofmt standards.