refactor: reuse shared command attestation

[Pigbibi]

Summary

• pin QuantPlatformKit to merged shared release-attestation contract
• replace LongBridge-local command release and runtime receipt validation with the common contract
• use the common reserved strategy_release intent field when producing paper commands

Verification

• targeted paper command producer/consumer tests: 9 passed
• lockfile validation passed
• import-order lint passed for changed application modules

Safety

• paper-only consumer remains observation-only and never imports an execution adapter
• no Cloud Run configuration, credentials, schedule, live setting, or deployment workflow changed