fix: reject malformed broker order responses

[Pigbibi]

Scope

• Stop converting missing/unknown order payloads or invalid rows into empty successful order reads.
• Preserve explicit empty lists and the existing supported wrapper shapes.
• Propagate a fixed sanitized failure through get_order_status; no broker payload logging, dependency or schema changes.

Validation

• RED: five malformed cases incorrectly returned success; ten valid shape cases passed.
• GREEN: 46 focused client/reconciliation/runtime-adapter tests passed with the pinned QPK/strategy source overlay and installed firstrade 0.0.39. Ruff and diff check passed.
• An initial broader attempt used an environment without firstrade; it was an environment failure, not a behavioral regression. No production dependency changed.

Remaining recovery limits

This does not establish account-history completeness, add the production reconciliation builder, refresh credentials, deploy, or activate trading.