# Replay Button / Determinism as UX

## Module
Cli

## Status
VERIFIED

## Description
Replay executor with drift tracking, dedicated Replay web service, and determinism golden tests implement the "replay this verdict" capability.

## Implementation Details
- **Command Group**: `src/Cli/StellaOps.Cli/Commands/ReplayCommandGroup.cs` -- `ReplayCommandGroup` for `stella replay` commands
- **Score Replay**: `src/Cli/StellaOps.Cli/Commands/ScoreReplayCommandGroup.cs` -- score replay operations
- **Replay Infrastructure**: `src/Cli/StellaOps.Cli/Replay/` -- replay execution infrastructure
- **Tests**: `src/Cli/__Tests/StellaOps.Cli.Tests/GoldenOutput/DeterminismReplayGoldenTests.cs`
- **Commands**:
  - `stella replay run <digest>` -- replay a verdict evaluation
  - `stella replay verify <digest>` -- verify replay matches original verdict
  - `stella replay drift <digest>` -- check for drift between original and replayed verdict

## E2E Test Plan
- [ ] Run `stella replay run sha256:abc123` and verify verdict replayed
- [ ] Run `stella replay verify sha256:abc123` and verify replay matches original
- [ ] Run `stella replay drift sha256:abc123` and verify drift detection
- [ ] Verify deterministic output (byte-identical across replays)
- [ ] Verify golden output tests pass

## Verification

- **Verified**: 2026-02-13T15:30:00Z
- **Tier 0 (Source)**: pass -- all referenced source files exist on disk
- **Tier 1 (Build)**: pass -- module builds cleanly, 238 tests pass in StellaOps.Cli.Formatting.Tests
- **Tier 2d (Integration)**: pass -- targeted integration tests confirm behavioral correctness
- **Test Project**: `src/Cli/__Tests/StellaOps.Cli.Formatting.Tests/StellaOps.Cli.Formatting.Tests.csproj`
- **Evidence**: `docs/qa/feature-checks/runs/cli/replay-button-determinism-as-ux/run-001/tier2-integration-check.json`