docs(#6638): fix doc comment guidance for injectable function variables

[fullsend-ai-coder]

Summary

Fixes inaccurate doc comment guidance in the "Injectable function variables (test seams)" section of docs/contributing/go-code.md. The merged text from PR #6200 documented a convention that doesn't match actual codebase usage, as flagged by the review agent.

Changes

• Doc comment rule: Changed from "starting with 'Override in tests to...'" to "following Go convention (starting with the variable name) that contains an 'Override in tests to...' sentence" — matching the actual pattern in RetrySleepFn, BuildWASMFn, execCombinedOutputFn, and resolveOverrideFn
• Unexported variants: Added note that both exported (XxxFn) and unexported (xxxFn) variables follow the Fn-suffix pattern, since the section previously only documented the exported form

Testing

• Verified the corrected rule matches actual doc comments in internal/sandbox/sandbox.go (RetrySleepFn), internal/dispatch/cf/provisioner.go (BuildWASMFn, execCombinedOutputFn), and internal/sandbox/gateway_endpoint.go (resolveOverrideFn)
• No Go code changes — docs-only, no test suite applies
• Pre-commit hooks passed (trailing whitespace, EOF, link checks)

Checklist

• PR title follows Conventional Commits (correct type, ! for breaking changes)

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Closes #6638

Post-script verification

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[fullsend-ai-review]

🤖 Finished Review · ✅ Success · Started 1:44 PM UTC · Completed 1:53 PM UTC

Commit: 9c2f8c7 · View workflow run →

Runtime: claude · Model: opus → claude-opus-4-6 · Effort: high · Cost: $2.35

[github-actions]

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Commit: 9c2f8c7c29c3388d836ca4173e9a322868abe42d

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

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[fullsend-ai-review]

Risk Assessment: moderate (2/5)

Details

Minimal 4-line documentation fix by a bot with no protected paths or security sensitivity; elevated only slightly above low due to high recent churn and multi-author activity on this actively-maintained contributing guide.

[fullsend-ai-review]

Looks good to me

[fullsend-ai-retro]

🤖 Finished Retro · ✅ Success · Started 9:55 AM UTC · Completed 10:07 AM UTC

Commit: 9c2f8c7 · View workflow run →

Runtime: claude · Model: opus → claude-opus-4-6 · Effort: high · Cost: $4.06

[fullsend-ai-retro]

Retro: PR #6641 — docs fix for injectable function variable guidance

Workflow quality: excellent. The retro → triage → code → review → merge pipeline worked as designed with zero rework. The code agent produced the correct 2-line fix on its first attempt, the review agent correctly approved, and the human reviewer concurred.

Timeline

1. Review agent flagged two accuracy issues on PR #6200 (Aug 13), but findings were posted as COMMENTED and went unaddressed.
2. PR docs(#6197): document Fn suffix convention for injectable function variables #6200 merged Aug 26 with findings ignored → retro agent filed #6638.
3. Triage ($0.95) → Code ($1.77) → PR #6641 created within 13 minutes.
4. Review agent approved ($2.35) → human approved next day → merged.

Total cost: $5.07. The ignored-findings rework cycle (duplicate review on #6200 + full triage/code/review for #6641) cost ~$8+ that would have been avoided if the original findings had been addressed.

Evidence for existing open issues

• #6018: Direct evidence — the review agent correctly flagged two accuracy issues on PR docs(#6197): document Fn suffix convention for injectable function variables #6200 as COMMENTED, the human approved without engaging, and a separate retro → issue → fix cycle was needed to resolve them. CHANGES_REQUESTED would have forced explicit dismissal.
• #2959: The review agent re-ran on PR docs(#6197): document Fn suffix convention for injectable function variables #6200 on Aug 26 and repeated identical Aug 13 findings verbatim, costing $3.58 with zero new information.
• #1900 / agents#373: $2.35 at hardcoded effort: high for reviewing a 2-line docs-only fix. No size-aware effort calibration exists.
• agents#427: On PR docs(#6638): fix doc comment guidance for injectable function variables #6641, the review agent correctly approved a straightforward docs correction; the human approved 20 hours later with no additional findings.