Native terms follow-up: no-plan terminal for unresolved HostSized groups and the remaining provenance witnesses - #252

Follow-up to #251 (R4-B native execution terms), addressing the final Fable review's remaining P1 and P2 items on the merged tree (cherry-pick of ff56aa9 onto e7cdf05).

What changes

• Runtime (10 lines, src/native_execution_consumer.cpp): a current finite-nonpositive group exhaustion with an unresolved HostSized binding and no executable plan now bypasses provisional inspection, installs its terms receipt and returns Cancelled{Group}; queued finite-nonpositive input still returns NonpositivePrice with the attempted terms. Native route only; the generated (legacy) route does not reach this code.
• Tests: Stop / Trail / StopLimit sibling, activation and provenance witnesses; replacement, StopLimit and BeginTrail non-transfer, gap (incl. exact-level gap) and replay controls as literal rows; partial/oversized CloseOpposite, bound HostSized rematch units, HostSized NaN preview/execute, injected post-binding NoChange, explicit-Transact preview units, SelectedExposure, percent-fee/marked-equity short accounting.
• Docs: the v15 controls sentence in docs/pages/abi-stability.md; W2 coverage table corrected (A-O1 remaining, deferred to slice C; A-F4 forward subrow removed by A9).

Invariants

• The six measured files (engine_strategy_commands.cpp, engine_fills.cpp, engine_orders.cpp, engine_risk.cpp, engine_run.cpp, engine_market_admission.cpp) are byte-identical to main.
• No epoch change (native_order v4, engine_script_run v15, native-consumer v6, broker/stream 15, driver v4, PF_ABI_VERSION 4). R-EPOCH scans zero hits.

Evidence (attached as it lands)

• Local ci_verify release on the exact head.
• One full Cloud sweep (4190 probes) on this exact tree vs the R4-B reference, snapshot, actual pr-gate (the expected target.not-positive FAIL retained; baseline promotion deferred).

🤖 Generated with Claude Code

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