Model Version Change Detection

Module

Scanner

IMPLEMENTED

Change detection for EPSS model version updates that suppresses noisy deltas when the underlying model changes, preventing false signal cascades.

EPSS Model Version Tracking:
- src/Scanner/__Libraries/StellaOps.Scanner.Storage/Epss/EpssCsvStreamParser.cs - EpssCsvStreamParser detects model version tags (e.g., v2024.01.15) from EPSS CSV data feeds and tracks version changes
- src/Scanner/__Libraries/StellaOps.Scanner.Storage/Epss/EpssExplainHashCalculator.cs - EpssExplainHashCalculator includes ModelVersion in explain hash calculations to distinguish model-driven vs real-world score changes
Change Detection:
- src/Scanner/__Libraries/StellaOps.Scanner.Storage/Epss/EpssChangeDetector.cs - EpssChangeDetector detects score changes between EPSS updates
- src/Scanner/__Libraries/StellaOps.Scanner.Storage/Epss/EpssChangeRecord.cs - EpssChangeRecord model for recording detected changes with model version context
Events:
- src/Scanner/__Libraries/StellaOps.Scanner.Storage/Epss/Events/EpssUpdatedEvent.cs - EpssUpdatedEvent includes ModelVersionTag to flag model-version-driven updates
- src/Scanner/__Libraries/StellaOps.Scanner.Storage/Epss/EpssReplayService.cs - EpssReplayService replays EPSS data with model version awareness for noise suppression

Ingest two EPSS CSV feeds with the same model version and verify genuine score changes are detected
Ingest an EPSS CSV feed with a new model version tag and verify the model version change is detected
Verify that when a model version changes, score deltas are flagged as model-driven rather than generating false signal cascades
Verify the explain hash includes model version so that model-change deltas are distinguishable from real-world changes
Verify the replay service correctly handles model version transitions without generating spurious change events