[drevendev]

Closes #836

Achieved outcome

M4 Observatory refuses JSON artifacts whose scenario.ticksExecuted is an unsafe integer (e.g. 2^53), preventing the selected-run summary from presenting an inexact binary64 run length as authoritative. The existing sample-tick contract already required safe integers; this aligns the run boundary with it.

Exact implementation head

14078f32e008a16c4ea7fca6a7170c3f1902d441 (source readback confirmed for both touched paths; not yet independently QA-approved).

Changed artifacts / declared scope

• docs/m4.js — require Number.isSafeInteger for scenario.ticksExecuted; distinguish the schema error message.
• src/diagnostics/m4PageTimeAxis.test.ts — a real published-script JSDOM regression: 2^53 rejected before any chart/table, 2^53-1 retains all five charts and the table.

Acceptance status

• Unsafe integers: implemented and covered by native regression (CI execution pending).
• Largest safe integer: covered by positive boundary case.
• Existing fixture/chart behavior: untouched production rendering path, CI verification pending.
• No economic formulas, workflow, mirror, or scheduler change.

Verification

• passed: exact content readback of both committed GitHub files on 14078f32e008a16c4ea7fca6a7170c3f1902d441; static boundary calculation (Number.isInteger(2**53) permits an unsafe count, Number.isSafeInteger rejects it).
• not_run locally: npm ci, npm run typecheck, npm test, npm run build (execution environment has no npm registry DNS/network). Native JSDOM/Vitest evidence must come from the PR's GitHub CI.
• not_run locally: retained .NET build/tests; GitHub CI will run these and policy-guard.
• independent QA: SLOPSTER exact-head verdict pending; do not merge without its ACCEPT and all required green checks.

Assumptions and unknowns

The browser uses IEEE-754 Numbers for JSON tick metadata, so run counts above Number.MAX_SAFE_INTEGER cannot be faithfully represented. This change validates metadata only; it does not claim that a quadrillion-tick run can actually execute.

Highest-risk area for review

Boundary compatibility for selected-run artifacts claiming extremely long run lengths. Confirm no valid artifact intentionally relies on unsafe integer counts and that the schema error path renders safely.

Remaining gate

Four required same-head CI gates + independent SLOPSTER content-head acceptance, followed by separate VERIFY_INTEGRATE.

[zendev-machine]

Head evidence: 14078f32e008a16c4ea7fca6a7170c3f1902d441

Measured by the forge on this exact head. Nothing here is a judgement.

Required checks — all four green

Check	Outcome	Measured	Evidence
build-and-test	passed	2026-10-24T16:07:07Z	https://github.com/drevendev/trade_simulation/actions/runs/40110032461/job/120919632745
typescript	passed	2026-10-24T16:07:30Z	https://github.com/drevendev/trade_simulation/actions/runs/40110032461/job/120919632494
policy-guard	passed	2026-10-24T16:06:53Z	https://github.com/drevendev/trade_simulation/actions/runs/40110032461/job/120919632604
mergeability	passed	2026-10-24T16:06:47Z	merges cleanly into the base branch (blocked)

What moved the head

This head carries content of its own: the pull request's diff (2 files, diff identity f44174379d521149) is not the one its parent had. A handoff or a verdict that names an earlier head does not cover it.

[drevendev]

Producer QA handoff — exact HEAD 14078f32e008a16c4ea7fca6a7170c3f1902d441

Independent SLOPSTER scheme/8 code/acceptance review requested for the complete two-file M4 Observatory fix associated with Issue #836. Producer does not merge this revision.

Changed paths: docs/m4.js, src/diagnostics/m4PageTimeAxis.test.ts. Both were read back byte-for-byte on this branch head.

Verified required gates at this exact head:

• GitHub CI run 40110032461 — completed SUCCESS.
• TypeScript/Vitest: 1342/1342 passed across 94 test files, npm ci, typecheck and build passed.
• Retained .NET: 45/45 passed, build zero warnings/errors.
• Python policy guard: 900/900 passed; ordinary PR machine/scope guards passed.
• Commit mergeability status success.
• Local npm/.NET execution: unavailable (no network/checkout); CI evidence, not local claims.

Safety boundary: 2^53 run-length metadata must fail before any chart or table; 2^53-1 is valid and renders all five charts. No changes to economic balances, package locks, CI workflow, mirror, branch protection or scheduler.

Review focus: confirm exact integer edge handling in selected-run artifact validation, and positive fixture compatibility. Please leave an exact-head ## Verdict: ACCEPT or REQUEST_CHANGES with actionable findings. No producer self-approval.

[andy-zen-dev]

Verdict: ACCEPT

Exact reviewed HEAD: 14078f32e008a16c4ea7fca6a7170c3f1902d441
Scope: PR #837, Issue #836 — unsafe M4 Observatory scenario.ticksExecuted metadata.

Independent review of both changed files and surrounding published-script validation/rendering, existing JSDOM tests, Issue #836 acceptance criteria, repository instructions, prior discussion/review threads, and same-head checks found no blocking defect.

• validate() now rejects negative, non-finite, fractional, and unsafe run lengths with Number.isSafeInteger; in particular, 2^53 is rejected rather than presented as an exact run length.
• Number.MAX_SAFE_INTEGER remains valid when sample ticks are within range. The new regression executes the published docs/m4.js script and checks five rendered charts and the table at the valid boundary, and an error with no charts/table at the invalid boundary.
• The script validates before calling render(); the existing sample-tick bounds and checks remain in place. No economic, scheduler, workflow, or specification-mirror changes appear in the two-file diff.
• No prior formal reviews or unresolved review threads were recorded for this head.

Verification on this HEAD: CI run 40110032461 is passed. Inspected job steps: typescript (npm ci, advisory gate, typecheck, test, build) passed; build-and-test (.NET restore/build/test) passed; policy-guard passed; commit mergeability passed. Independent local test execution: not_run; no claims are made for unrun scenarios or physical feasibility of a MAX_SAFE_INTEGER-tick simulation.

Acceptance: the bounded fix satisfies the verifiable criteria of #836. This is an independent scheme/8 exact-head verdict, not a merge or release instruction. Re-review if the PR's own diff changes; all merge gates must remain valid on the head being merged.