docs: architectural audit v3.4.0 (2026-03-26)

[carlos-alm]

Summary

• Full architectural audit of codegraph v3.4.0 — first audit for this project
• Scored 6.8/10 overall with key findings: 29% caller coverage, 37-file MCP barrel cycle, 1,851-line types.ts coupling hub
• Competitive verification against Sourcegraph, Joern, Semgrep, stack-graphs, narsil-mcp — codegraph occupies a unique niche (local + deterministic + function-level + MCP + 11 languages + 3 deps)
• Strategic verdict: conditional invest — fix caller coverage as Bump actions/setup-node from 4 to 6 #1 priority
• ADR compliance review with 4 missing ADRs identified
• Dead code breakdown showing 8,960 headline number is 93% non-actionable (leaf nodes, unresolved imports, entry points, FFI)

Test plan

• Verify audit file renders correctly in GitHub markdown
• Confirm all codegraph command outputs are current
• Cross-check competitor claims against linked sources