feat: Remediate hasna/machines#83 bounded-exec review blockers

[hasna-identity]

Objective

Remediate #83 bounded-exec review blockers

Remediation cycle one for PR #83 exact reviewed tree. Add failing regression tests before production changes for exactly four named P1s: pre-materialization 65,536-character script input bound; collection-time stdout/stderr bound whose returned value including suffix obeys maxOutputChars; AWS_SECRET_ACCESS_KEY assignment redaction using synthetic fixtures only; and private machine route secrecy in unsafe-target errors. Apply the smallest owning fixes, preserve stream separation, exit propagation, timeout behavior, and safe shell quoting. Update the existing PR branch, include exactly one Agent: agent-ea trailer and no Co-Authored-By, run affected tests plus verify:release and staged secret scan, and return the exact new head to the same reviewer Feynman for focused re-review only. Do not merge, publish, install, use raw ssh, inspect real credential values, or broaden scope.

Verification

• policy source: base 63cfb00 (immutable commit — agent-proof)
• containment: env — allowlist env, non-login shell, run-scoped HOME (registry auth seeded for install)
• install: pass
• typecheck: pass
• build: pass
• test: pass
• doctor (ci): ok — 11 checks passed (1 advisory)

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Run run_6e5babcb9f79 · backend cursor · task 20945ea8-b45b-4ffa-a8b7-c86b43097560
🏭 Generated by @hasnaxyz/factory

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[andrei-hasna]

[REVIEW] NO_GO — #84 @ 1d16140 — lens: correctness+security+gates, reviewer Trebius (1 of 1)

Reviewed the full origin/main...HEAD diff against freshly fetched base bc7123fac90af90e9a3844dc7489d46ca2ddb256, including every changed file and the surrounding CLI dispatch, remote runner/process-group timeout, SSH target validation, mutation-approval, redaction, and test code.

Commands and exact results:

• bun install — exit 0; setup only, 116 packages installed.
• bun run typecheck — exit 0; pass, no count emitted by tsc --noEmit.
• bun run test — exit 0; 559 pass, 0 fail, 559 tests across 62 files.
• Real-path control: bun src/cli/index.ts exec --machine local --timeout-ms 5000 -- sh -c 'exit 37' — exit 37. No approval token or trusted-local mutation opt-in was supplied, so the propagated 37 proves the command executed.

Blocking P0/P1 findings:

• P1, high confidence — machines exec bypasses the package mutation-approval boundary (src/cli/index.ts:3220-3263). The action exposes no --approval-token and calls runMachineExec directly, unlike the repository's other mutating CLI paths. Source → flow → sink: unapproved argv or script → runMachineExec → runMachineCommand → local bash -c or remote ssh, allowing arbitrary filesystem, package, service, or data mutation. The real CLI control above confirms this is currently reachable at the reviewed head. Remedy: require the existing scoped machines_exec approval before invoking the runner, binding the exact machine, timeout, effective output cap, and argv or script; add denial, exact-token success, and tamper regressions.

Non-blocking follow-ups:

• None.

[andrei-hasna]

Fixed the named mutation-approval blocker in c4cb243.

• Added the scoped machines_exec mutation operation and --approval-token CLI option.
• Bound approval to the exact machine, timeout, effective output cap, and argv or script payload.
• Added denial, exact-token success, changed-argv rejection, propagated failure, timeout, and script regressions.
• Post-fix real-path control: the same unapproved command now prints Fleet mutation blocked: cli.machines_exec requires operator approval... and exits 1.
• bun run typecheck — exit 0.
• bun run test — exit 0; 559 pass, 0 fail, 559 tests across 62 files.
• shield review on the staged four-file remediation — exit 0; No security issues found in staged changes.

[andrei-hasna]

[REVIEW] GO — #84 @ e88dbf0c9d8a95ba3ac6d8d1e2746db8d550aa7f — lens: correctness+security+gates, reviewer Trebius (1 of 1)

Focused re-review of the sole named blocking defect, its fix, and direct regressions.

Remediation:

• machines exec now requires the existing scoped machines_exec mutation approval before runner invocation.
• Approval binds the exact machine, timeout, effective output cap, and argv or script payload.
• The real unapproved CLI control now prints the approval-required refusal and exits 1; exact-token success and changed-command rejection are covered by regression tests.
• e88dbf0c9d8a95ba3ac6d8d1e2746db8d550aa7f reconciles current main into the PR. Its tree is byte-identical to the reviewed c4cb243593a27e20d16ed9c19cf25c4463b86fab tree.

Affected and required gates:

• bun run typecheck — exit 0 after the fix; exit 0 again after conflict resolution.
• bun run test — exit 0; 559 pass, 0 fail, 559 tests across 62 files on the exact tree now at the PR head.
• shield review on the staged four-file fix — exit 0; No security issues found in staged changes.
• Fresh merge-tree check against origin/main — exit 0; merge tree equals the PR head tree.

Blocking P0/P1 findings: none remain.

Non-blocking follow-ups: none.

[andrei-hasna]

[REVIEW] GO — #84 @ e88dbf0 — lens: correctness+security+gates, reviewer Trebius (1 of 1)

This supersedes the immediately preceding GO comment, which expanded the short head SHA incorrectly and is therefore stale.

Focused re-review of the sole named blocking defect, its fix, and direct regressions:

• machines exec now requires scoped machines_exec mutation approval before runner invocation, bound to the exact machine, timeout, effective output cap, and argv or script payload.
• The real unapproved CLI control now prints the approval-required refusal and exits 1; exact-token success and changed-command rejection are covered by regression tests.
• This head reconciles current main into the PR, and its tree is byte-identical to the reviewed and tested c4cb243593a27e20d16ed9c19cf25c4463b86fab tree.

Affected and required gates:

• bun run typecheck — exit 0 after the fix and exit 0 after conflict resolution.
• bun run test — exit 0; 559 pass, 0 fail, 559 tests across 62 files on the exact tree now at the PR head.
• shield review on the staged four-file fix — exit 0; No security issues found in staged changes.
• Fresh merge-tree check against origin/main — exit 0; merge tree equals the PR head tree.

Blocking P0/P1 findings: none remain.

Non-blocking follow-ups: none.