feat: publish Firstrade runtime target lifecycle

[Pigbibi]

Summary

• add a read-only hourly lifecycle monitor for the Firstrade runtime target
• distinguish a deliberately disabled target from a failed execution heartbeat
• publish only sanitized monitor state to the protected unified control plane
• align the stale QuantPlatformKit pin required by the repository CI gate

Validation

• runtime-binding privacy guard passed
• QPK pin consistency check passed against QPK main
• uv lock --check passed
• diff whitespace check passed

This workflow cannot enable a target, alter its execution lane, access broker credentials, or submit an order.