feat: make GenLayer consensus a first-class Assay trust layer

[Franlinozz]

Summary

Merges the completed GenLayer integration into the default branch before the GenLayer Builder Project submission.

• adds AssayAdjudicator Intelligent Contract and Bradbury deployment evidence
• adds GenLayer wallet/transaction lifecycle to the Studio
• inserts Consensus before the existing X Layer seal
• preserves OKX.AI/x402 and X Layer behavior
• adds GenLayer direct/integration tests, CI gate, docs, security boundary, and submission pack
• updates public positioning so GenLayer is the primary adjudication layer while X Layer remains integrity sealing

Submission-critical evidence

• Bradbury contract: 0xa0A37DEf61d5C621FDeF43b604D8059779D1B96E
• live app: https://assayed.xyz
• submission pack: docs/GENLAYER-SUBMISSION.md
• deployment transcript: docs/GENLAYER-BRADBURY.md

This PR is intentionally opened before submission so GitHub Actions can validate the exact code intended for main.