test(trading): qualify lane A OVERNIGHT stage admission - #1095

Scope

Main's adaptive-paper preflight refuses an OVERNIGHT stage start. #1081 already implements the qualified overnight port and admission branch; this stacked draft adds a fail-before acceptance pack and retained venue evidence for lane A without duplicating that implementation.

• Base commit: ea0a51a6b2a485977d8aaf8e11dc0e93fe820a06, Arm bounded overnight REST diagnostics with owned lifecycle and residual exits #1081 (foundation/overnight-arming-20261013). Main fail-before pin: 04f64a056cade587f804da60f6a94f7852f7624d.
• Lane: lane:trading.
• Owned paths: the new overnight acceptance test, README and dated decision; two new public evidence files; native registrations in manifests/evidence.json.
• Depends on Arm bounded overnight REST diagnostics with owned lifecycle and residual exits #1081's reviewed landing. Keep this PR draft until its owning-lane reads and retargeting are complete.

The new regression accepts 21:00 ET only with the existing BOATS REST/overnight configuration and coupled extended-hours flags. Extended hours alone continues to refuse OVERNIGHT. An overnight stage is bounded at 04:00 ET; a DAY order's separate expiry at 20:00 ET cannot supply the missing cleanup window. The opted-in port retains must-end-flat, while PRE/RTH/POST/default-policy controls retain their existing behavior. Production source, source-hash manifests and frozen/shipped configurations are byte-unchanged against the parent.

SOTA sources

• native-agent-stack/native-agent-stack #1081, pin ea0a51a6b2a485977d8aaf8e11dc0e93fe820a06: blueprints/us-equities/adaptive-paper/runner.py (validate_preflight), sessions.py (validated overnight policy, order extended-hours flag, session close and must-end-flat), overnight.py and the existing reduce-only dispatch/ledger/wire guards. Reuses the port; does not rebuild it.
• Alpaca 24/5 Trading, vendor update 2026-07-07T14:17:11.000Z, retained 2026-10-10 capture. Public verbatim excerpt: evidence/artifacts/lane-a-overnight-acceptance-20261013/alpaca-245-trading-excerpt.md. Overnight is LIMIT-only; DAY carries to 20:00 ET of the trade date; DTBP does not apply and 2x is the maximum margin buying power. This is a ceiling, not a sizing target or account entitlement.
• NautilusTrader, 2.0.0rc5 at 1b0a49d2792a9432a3aca3fcb617ce7a630d905e: crates/model/src/enums.rs (TradingState::Reducing) and crates/risk/src/engine/mod.rs (is_reducing_submission and denial). Pinned source verified directly. The CC's 2026-10-13 06:11Z P1-B ruling uses this mechanism for the parent's residual exit path; this PR repeats its synthetic dispatch regression, not an engine E2E.

Evidence-class table

Retained results: evidence/artifacts/lane-a-overnight-acceptance-20261013/validation.json. The initial four-test module and exact final one-test main probe are distinguished there; neither is reported as a pass. Raw local traceback logs remain private, with no raw-log digest published.

Local commands run

TMPDIR=/var/tmp python3 -B -m unittest tests.test_adaptive_paper_overnight_acceptance.OvernightStartAcceptance.test_overnight_stage_start_is_admitted_only_with_qualified_flags
# genuine main worktree at 04f64a05: exit 1, 1 test / 1 error, regular_session_window_unavailable

TMPDIR=/var/tmp python3 -B -m unittest tests.test_adaptive_paper_overnight_acceptance
# implementation parent: exit 0, 6 tests

TMPDIR=/var/tmp python3 -B -m unittest tests.test_adaptive_paper_sessions
# exit 0, 151 tests, 34 optional native-runtime skips

TMPDIR=/var/tmp python3 -B -m unittest tests.test_adaptive_paper_leverage.RefusalTests.test_overnight_max_leverage_above_2_refused tests.test_adaptive_paper_leverage.RefusalTests.test_overnight_gross_exceeds_regt_refused tests.test_adaptive_paper_leverage.PropertyGridTests.test_overnight_cap_bounds_ceiling_at_2_in_every_session
# exit 0, 3 tests

TMPDIR=/var/tmp python3 -B -m unittest tests.test_adaptive_paper_overnight_arming.OvernightArming.test_pre_entry_remains_refused tests.test_adaptive_paper_overnight_arming.OvernightArming.test_held_overnight_position_exits_at_pre_as_extended_hours_limit
# exit 0, 2 tests

python3 -B scripts/validate.py
# exit 0; 71 components, 11956 hashed files, 4 profiles, 240 receipts

All five additions are registered through host_receipts.register_file. New-file native identity/email scan and gitleaks pass; the vendor excerpt's six paragraphs match the retained public capture verbatim. No allowlist or privacy-guard change was added by this PR.

Decision record

docs/decisions/2026-10-13-lane-a-overnight-acceptance.md; implementation/acceptance boundary in blueprints/us-equities/adaptive-paper/README-overnight-acceptance.md.

Host evidence

No host receipt or platform-status change.

Checklist

• No Actions or workflow change.
• No secrets or private identities added; raw local traces stay private.
• No new paid service, dependency, account operation or credential load.
• Peer-owned worktrees and PR heads preserved.
• No deployment or service/unit action.

Follow-ups

• Parent Arm bounded overnight REST diagnostics with owned lifecycle and residual exits #1081 must pass its own reads and land; retarget/rebase this draft afterward and reverify any changed admission/exit contract.
• Fresh merge-tree is clean against the pinned Arm bounded overnight REST diagnostics with owned lifecycle and residual exits #1081 parent. Against current main, inherited parent conflicts remain in mover.py, source-hashes.json and manifests/evidence.json; the parent owner resolves its implementation carry before this draft retargets. This PR does not edit those production or frozen files.
• Native-runtime and genuine overnight paper qualification remain owning-lane work. The 34 skips and synthetic dispatch do not establish entitlement, current BOATS data, fills, liquidity or broker reconciliation.
• Review the acceptance boundary before widening stages; the default flatten lead and must-end-flat rule remain constraints.