Spec design for baseline parity implementation

[aryeko]

Story

• baseline Parity-Capable App #70

Motivation

Baseline behavior must be precise because it anchors quality comparisons.

Scope

In:

• Scenario mapping
• Shared-contract usage plan
• Verification order

Out:

• Benchmark threshold tuning

Requirements

• Map fixture cases to baseline handlers
• Define seed/state behavior

Acceptance criteria

• Baseline design covers parity and run-single requirements

Verification

Commands:

• make -n parity-check

CI checks:

• (none)

Evidence:

• Baseline design mapping

Artifacts

• Design consumed by T-025..T-027

Spec reference

• .sisyphus/plans/apps-implementation-roadmap.md
• Section: ST-007
• Quote: baseline Parity-Capable App

Dependencies

Blocked by:

• Document anti-drift usage guidance #78