[deep-report] Document panic() contract for 8 embed-guarded lazy-load panic sites in pkg/workflow/pkg/actionpins #54316

Description

The Error Handling Consistency & Panic Safety report (discussion #54241, 2026-08-20) found 8 panic() call sites in pkg/workflow/pkg/actionpins that fire only if lazily-loaded, go:embed-ed JSON/config data fails to unmarshal — a condition that should be build-time-impossible. Verified live: pkg/workflow/model_aliases.go:91,148, pkg/actionpins/data.go:74,90,98, pkg/workflow/agentic_engine.go:557, pkg/workflow/permissions_toolset_data.go:44, pkg/workflow/pi_engine.go:149, pkg/workflow/mcp_setup_gateway.go:133, pkg/workflow/mcp_setup_safe_outputs.go:59. These currently rely only on the panic-in-library-code linter's incidental exemption for init-like patterns rather than an explicit documented contract, so a future refactor could unintentionally introduce a runtime panic path reachable from user input.

Expected Impact

Makes an implicit "should never happen" invariant explicit and linter-consistent, reducing the risk that a future change accidentally routes dynamic (non-embedded) data through one of these panic paths.

Suggested Agent

New Agent — add a one-line doc comment immediately above each panic() call stating it's an intentional, build-time-guarded invariant (matching the pattern in pkg/linters/panic-in-library-code/testdata/.../panicinlibrarycode.go around line 86). Verify each package already has a test that unmarshal-validates its embedded data file; add one if missing so a corrupted embedded file fails go test in CI rather than only surfacing as a runtime panic. Do not change panic behavior itself.

Estimated Effort

Medium (1-4 hours)

Data Source

DeepReport Intelligence Briefing analysis of discussion #54241 (Repository Quality Improvement Report - Error Handling Consistency & Panic Safety, 2026-08-20).

Generated by 🔬 Deep Report · agent · 163.9 AIC · ⌖ 8.4 AIC · ⊞ 11.9K · ◷

• expires on Aug 22, 2026, 10:32 AM UTC-08:00