Keep safe haven cash for unbuyable small accounts

[Pigbibi]

Summary

• zero the safe-haven target when whole-share projection removes the only non-safe-haven target
• expose the safe-haven cash substitution in the execution summary
• update pinned QuantPlatformKit and UsEquityStrategies versions for delayed IBKR quote snapshots and smart DCA localization
• add an IBKR execution test for the 15% SOXX / 85% BOXX small-account case

Verification

• python -m py_compile application/execution_service.py tests/test_execution_service.py
• Not run locally: python -m pytest tests/test_execution_service.py -k 'projects_unbuyable_weight_target_to_zero or keeps_safe_haven_cash_when_only_risk_target_is_unbuyable' (local Python environment is missing pandas)

[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Recompute realized safe-haven weight after cash substitution

When a small account's only positive risk target is projected to cash, this branch zeroes the safe-haven target but leaves execution_summary["realized_safe_haven_weight"] at the value computed earlier from the pre-substitution weights. In the new SOXX/BOXX scenario this means reconciliation/reporting can show an 85% realized safe-haven weight while target_vs_current and order generation treat BOXX as 0%, so the summary is internally inconsistent; update the realized safe-haven weight after this substitution.

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