docs(#346): add secure HTTP client guidance to Go section

[fullsend-ai-coder]

Add a "Secure HTTP clients" subsection under "Go code" in AGENTS.md documenting five required security properties for any new HTTP client that fetches external URLs: SSRF-safe dialer using netutil.CheckIP, HTTPS-only with redirect validation, no proxy, explicit timeout, and bounded reads via io.LimitReader. These patterns prevent the class of review-round fixes seen in PR fullsend-ai#3002.

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Closes #346

Post-script verification

• Branch is not main/master (agent/346-secure-http-client-guidance)
• Secret scan passed (gitleaks — a2afa8b179a351845733c680b839a39a82304db6..HEAD)
• Pre-commit hooks passed (authoritative run on runner)
• Tests ran inside sandbox

[fullsend-ai-review]

🤖 Finished Review · ✅ Success · Started 6:48 AM UTC · Completed 6:54 AM UTC
Commit: a2afa8b · View workflow run →

[fullsend-ai-review]

Review — PR #383

Verdict: Approve

Summary

This PR adds a well-crafted "Secure HTTP clients" subsection under "Go code" in AGENTS.md, documenting five required security properties for any new HTTP client that fetches external URLs. The change delivers exactly what issue #346 authorized with no scope creep.

Dimension results

Dimension	Result
Correctness	✅ All five technical claims verified against Go stdlib behavior and the existing codebase. netutil.CheckIP exists at internal/netutil/ip.go and covers loopback, private, link-local, multicast, unspecified, and additional reserved CIDRs — matching the doc's description. http.DefaultClient has no timeout (correct). Transport.Proxy = nil disables env-var proxy routing (correct). io.LimitReader is the standard bounded-read pattern (correct). CheckRedirect is a real http.Client field (correct).
Security	✅ Clean. No secrets, no injection patterns, no Unicode steganography, no permission changes. Pure documentation addition.
Intent & coherence	✅ Scope matches issue #346 exactly — five properties, same defaults, same file, same section. No scope creep. Architecturally coherent: the subsection sits naturally as a level-3 heading under "## Go code", parallel to "### Running e2e tests".
Style & conventions	✅ Formatting is fully consistent: heading level, bold labels with em-dashes, numbered list structure, backtick usage for code elements, and bold must for policy statements all match existing AGENTS.md patterns.
Documentation currency	✅ Referenced identifier netutil.CheckIP verified at internal/netutil/ip.go. Existing implementation in internal/fetch/fetch.go validates all five documented properties. No stale references introduced.
Cross-repo contracts	⏭ Skipped — no exported interfaces, schemas, or public APIs modified.

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Protected paths detected — this PR modifies files under one or more
protected paths. The review agent cannot approve PRs that touch these paths.
A human reviewer must approve this PR.

Protected files in this PR:

• AGENTS.md

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Labels: PR adds security-related documentation guidance to AGENTS.md

[guyoron1]

/fs-fix

[fullsend-ai-coder]

🤖 Finished Fix · ✅ Success · Started 7:58 AM UTC · Completed 8:03 AM UTC
Commit: a2afa8b · View workflow run →

[fullsend-ai-coder]

🔧 Fix agent — iteration 1 (human-triggered)

No changes made. The review agent approved this PR with no findings. The human /fs-fix command included no specific instruction. There are no actionable items to fix.

Disagreed (1):

1. no actionable findings: The automated review agent approved PR docs(#346): add secure HTTP client guidance to Go section #383 with no changes requested — all dimensions (correctness, security, intent & coherence, style & conventions, documentation currency) passed. The human triggered /fs-fix without a specific instruction. There are no review findings to address and no human-directed changes to make.

Tests: passed

_{Updated by fullsend fix agent}