fix(engine): make dead strategy.close semantically inert

[luisleo526]

Summary

• make deferred-flip carry depend on runtime order state instead of the global script_has_strategy_close_ AST bit
• retain the legacy bit as a no-op so existing generated classes remain source-compatible
• add a metamorphic regression test proving an unreachable strategy.close cannot change bracket-exit fills
• update existing characterization coverage and runtime documentation

Fixes #141.

Root cause

Codegen set script_has_strategy_close_ from textual AST presence, without reachability analysis. The runtime used that global bit to gate placement-time reversal carry, so adding an unreachable strategy.close changed later priced-entry quantities even though the executed broker commands were identical. A strategy.exit bracket can close the carry source on its own, so the runtime decision must use the order's captured state rather than unrelated source text.

Validation

• full build succeeded
• CTest: 123/123 passed
• fresh locked Corpus A/B: 312/312 on both sides; 0 tier DOWN, 0 metric DOWN, 0 gate DOWN; the only changed probe remained Excellent and improved six metrics
• full downstream strategy A/B: terminal classifications, grade rows, and trade tapes were identical; 0 tier DOWN, 0 countAbsDelta regressions, 0 Excellent-to-below-Strong regressions, 0 unresolved failures
• downstream E+S remained neutral; owner explicitly approved the byte-identical no-regression result for this correctness fix

[Copilot]

Pull request overview

This PR fixes the deferred-flip carry behavior so that adding an unreachable strategy.close in Pine source cannot change runtime backtest fills. It removes the runtime dependency on the compile-time script_has_strategy_close_ AST bit, keeps that bit only for generated-code compatibility, and adds regression/characterization coverage plus runtime documentation updates.

Changes:

• Remove script_has_strategy_close_ from the deferred-flip predicate in BacktestEngine::enter_market_from_flat.
• Reframe script_has_strategy_close_ as a legacy, semantically inert compatibility member in engine headers and runtime docs.
• Update/add tests to prove unreachable strategy.close is inert and adjust characterization expectations where carry behavior is now pinned correctly.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/engine_orders.cpp	Drops the compile-time flag from the deferred-flip carry condition so behavior depends only on order-captured runtime state.
include/pineforge/engine.hpp	Documents script_has_strategy_close_ as legacy compatibility only (no runtime semantic effect).
tests/test_strategy_pyramiding.cpp	Removes direct flag forcing and adds a metamorphic regression test for issue #141.
tests/test_same_id_stop_replace.cpp	Updates commentary to reflect the new deferred-flip predicate (no compile-time gate).
tests/test_close_all_coqueued_entry.cpp	Updates characterization to match generated-script behavior and pins expected carry outcome.
docs/cheatsheet-runtime-and-execution.md	Updates runtime cheat sheet to reflect that the flag no longer gates deferred-flip behavior and that brackets can arm carry behavior.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.