feat: define Ralph governed implementation preset

[devkade]

Summary

Define Ralph as a governed implementation preset in the RunContract Harness.

Parent roadmap: #114
Track: C - Preset evolution
Related: #118, #167

Problem

Ralph is the implementation/build preset, but its RunContract-facing contract is not yet explicit. Without a preset contract, Ralph behavior can drift into ad hoc planning, implementation, verification, and closeout rules that are harder to compare with Deep Interview, Autoresearch, and Integrate.

Scope

• Define the Ralph governed implementation preset contract.
• Specify the preset goal shape, required inputs, expected artifacts, evidence standard, done criteria, repair criteria, and closeout expectations.
• Define how Ralph consumes a Deep Interview RunContractDraft without making the draft a second source of truth.
• Keep implementation governance generic and free of GitHub/PR/Ragna/kapi-agent assumptions.
• Identify follow-up implementation slices if the design reveals missing behavior.

Non-goals

• No broad Ralph runtime rewrite.
• No worker scheduler or policy-learning implementation.
• No durable contract.json source of truth.
• No GitHub/PR/kapi-agent semantics in RunContract core.
• No command rename or storage-root migration.

Acceptance criteria

• Ralph preset contract is documented or implemented with tests.
• Required artifacts and evidence expectations are explicit.
• Done/repair/closeout criteria are defined.
• Deep Interview handoff behavior is specified without duplicating the RunContractDraft as authority.
• The preset remains generic and does not absorb adapter-specific workflow policy.

Verification

• Design review against Kapi → Ilchul RunContract Harness roadmap #114 RunContract boundary.
• Review against feat: define Deep Interview RunContractDraft artifact #118 RunContractDraft handoff semantics.
• Relevant Ralph workflow tests if implementation changes are included.