Verified verdict: the run-level PASS/FAIL rule (FR-004 of #6656) #6731

Goal

Epic #6655, MVP #6656 FR-004: "Produce a machine-readable PASS/FAIL verdict." Every phase rule now names its own codes (reuse #6671, seal_check #6708, evidence_chain #6693, region #6717, device_evidence #6720), but nothing defines the run's final answer -- what PASS means once every rule has spoken, and which references a record must name before it may be read at all.

Where we are

.trinity/seals/*.json are the machine-readable records; the missing piece is the rule a third party applies to one: the three references (run, artifact, evidence), the software verdict, and the honesty of the hardware field.

Boundary

• specs/verified/verdict.t27 only: run_verdict (PASS iff the chain is LINKED), record_status (references judged in fixed order before the verdict), hw_field_honest (the hw field verbatim from device_evidence, never upgraded by a passing software verdict).
• No orchestrator that emits one JSON blob per run -- that is tooling, parked under the only-t27 rule.

User Scenarios & Testing

• Given a record naming run, artifact and evidence with a whole chain, when the rule runs, then the verdict is PASS.
• Given a record missing any reference, when the rule runs, then it is INVALID and names the missing reference, before any chain code is read.
• Given a PASS record whose hardware field says VERIFIED while the evidence says UNPROVEN, when the rule runs, then the hw field is dishonest and the rule says so.

Requirements

• FR-001: run_verdict composes evidence_chain.LINKED; a broken link is one FAIL with the link code as the reason.
• FR-002: record_status judges references run -> artifact -> evidence, then the verdict.
• FR-003: hw_field_honest is exact equality with device_evidence's state; PASS never implies hardware.
• FR-004: tests pin literal codes so renumbering the constants cannot pass; mutation-checked on the lab.

Success Criteria

• zig test green on the Railway lab with master's t27c; every mutant killed by a test assert; seal saved and verified MATCH; closes the FR-004 gap of MVP: prove one verified incremental FPGA update end-to-end #6656.