Walk Track: Follow-up backlog epic

[nikhil2611]

Epic: Walk Track AI-assisted findings — follow-up work

Source: Walk Track exercises Ex1–Ex11

Child Issues

Issue	Title	Size
#140	Extend test_mandatory_field refactor to remaining commands	Medium
#141	Add contract tests for NodePresenter JSON boundary	Small
#142	Extend debug timing to search, node_list, ssh	Small
#143	Add doc link-checker CI step	Small
#144	Add Brakeman SAST scan to CI	Small

Dependency Graph

#143 (link check)   ── standalone
#144 (SAST)         ── standalone
#142 (timing)       ── follows Walk Ex9 pattern (merged)
#141 (NodePresenter)── follows Walk Ex5 pattern (merged)
#140 (refactor)     ── start here; safer after #141 adds coverage

Suggested Delivery Order

1. Walk Track: Add doc link-checker CI step #143 + Walk Track: Add Brakeman SAST scan to CI #144 — parallel, CI-only, no source changes
2. Walk Track: Extend debug-level timing instrumentation to search, node_list, ssh #142 + Walk Track: Add contract tests for NodePresenter JSON boundary #141 — parallel, follow established patterns
3. Walk Track: Extend test_mandatory_field refactor to remaining knife commands #140 — after Walk Track: Add contract tests for NodePresenter JSON boundary #141 increases coverage safety net

Backlog Doc

docs/backlog-walk.md