partly or unimplemented features - now implemented

docs/features/unchecked/policy/delta-if-present-calculations-for-missing-signals.md

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+# Delta-If-Present Calculations for Missing Signals
+
+## Status
+NOT_FOUND
+
+## Description
+The advisory proposed computing "delta if present" values showing what would change if missing signals arrived (TSF-004). This was marked TODO and has not been implemented.
+
+## Why Not Implemented
+- The specific "delta-if-present" calculation (TSF-004) for showing hypothetical score changes is not implemented as a standalone feature
+- However, related infrastructure exists in the Policy Determinization module:
+  - `src/Policy/__Libraries/StellaOps.Policy.Determinization/Models/SignalGap.cs` -- models for missing/gap signals
+  - `src/Policy/__Libraries/StellaOps.Policy.Determinization/Scoring/UncertaintyScoreCalculator.cs` -- calculates uncertainty from missing signals
+  - `src/Policy/__Libraries/StellaOps.Policy.Determinization/Scoring/PriorDistribution.cs` -- prior distributions for gap handling
+  - `src/Policy/__Libraries/StellaOps.Policy.Determinization/DeterminizationOptions.cs` -- configuration for determinization behavior
+  - `src/Policy/StellaOps.Policy.Engine/Simulation/RiskSimulationBreakdown.cs` -- risk simulation with breakdown
+  - Tests: `src/Policy/__Tests/StellaOps.Policy.Engine.Tests/Simulation/RiskSimulationBreakdownServiceTests.cs`
+- The Determinization module handles missing signals by computing uncertainty scores but does not project "what would change if signal X arrived" as a delta preview
+- Graph module also tracks missing signals: `src/Graph/__Libraries/StellaOps.Graph.Core/ICveObservationNodeRepository.cs`
+
+## Source
+- Feature matrix scan
+
+## Notes
+- Module: Policy
+- Modules referenced: `src/Policy`
+- Related: `src/Policy/__Libraries/StellaOps.Policy.Determinization/` (uncertainty scoring for gaps)