semi implemented and features implemented save checkpoint

docs/features/unchecked/releaseorchestrator/promotion-decision-engine.md

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+# Promotion Decision Engine (Gate + Approval Combination)
+
+## Module
+ReleaseOrchestrator
+
+## Status
+IMPLEMENTED
+
+## Description
+Decision engine combining gate evaluation results and approval status into final promotion decisions. Generates decision records with evidence, supports configurable decision rules, and maintains decision history.
+
+## Implementation Details
+- **Modules**: `src/ReleaseOrchestrator/__Libraries/StellaOps.ReleaseOrchestrator.Promotion/Decision/`
+- **Key Classes**:
+  - `DecisionEngine` (`src/ReleaseOrchestrator/__Libraries/StellaOps.ReleaseOrchestrator.Promotion/Decision/DecisionEngine.cs`) - combines gate evaluation results and approval status into promotion decisions
+  - `DecisionRecorder` (`src/ReleaseOrchestrator/__Libraries/StellaOps.ReleaseOrchestrator.Promotion/Decision/DecisionRecorder.cs`) - records decision outcomes with evidence for auditability
+  - `DecisionRules` (`src/ReleaseOrchestrator/__Libraries/StellaOps.ReleaseOrchestrator.Promotion/Decision/DecisionRules.cs`) - configurable rules for combining gate and approval results
+- **Interfaces**: `IDecisionEngine`
+- **Source**: SPRINT_20260110_106_005_PROMOT_decision_engine.md
+
+## E2E Test Plan
+- [ ] Submit gate results and approval status to `DecisionEngine` and verify a promotion decision is produced
+- [ ] Verify decision with all gates passing and approval granted results in "Approved" decision
+- [ ] Verify decision with a failing gate results in "Rejected" decision regardless of approval status
+- [ ] Verify `DecisionRecorder` persists decision records with evidence references
+- [ ] Configure custom `DecisionRules` and verify the engine applies them correctly
+- [ ] Query decision history and verify past decisions are retrievable