semi implemented and features implemented save checkpoint

docs/features/unchecked/cli/replay-button-determinism-as-ux.md

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+# Replay Button / Determinism as UX
+
+## Module
+Cli
+
+## Status
+IMPLEMENTED
+
+## 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