more features checks. setup improvements

docs/features/checked/signals/nightly-unknowns-decay-batch-worker.md

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+# Nightly Unknowns Decay Batch Worker
+
+## Module
+Signals
+
+## Status
+VERIFIED
+
+## Description
+Scheduled background worker that runs nightly to apply exponential confidence decay to unknown/unresolved findings, automatically reducing their priority scores over time based on configurable decay curves and age thresholds.
+
+## Implementation Details
+- **Modules**: `src/Signals/StellaOps.Signals/Services/`, `src/Signals/StellaOps.Signals/Options/`
+- **Key Classes**:
+  - `NightlyDecayWorker` (`src/Signals/StellaOps.Signals/Services/NightlyDecayWorker.cs`) - background service that runs nightly decay processing
+  - `UnknownsDecayService` (`src/Signals/StellaOps.Signals/Services/UnknownsDecayService.cs`) - applies exponential confidence decay to unknown/unresolved findings
+  - `UnknownsDecayOptions` (`src/Signals/StellaOps.Signals/Options/UnknownsDecayOptions.cs`) - configurable decay curves and age thresholds
+  - `UnknownsDecayMetrics` (`src/Signals/StellaOps.Signals/Services/UnknownsDecayMetrics.cs`) - telemetry metrics for decay operations
+- **Interfaces**: `IUnknownsDecayService`
+- **Source**: SPRINT_3601_0001_0001_unknowns_decay_algorithm.md
+
+## E2E Test Plan
+- [ ] Configure `UnknownsDecayOptions` with a decay curve and verify `NightlyDecayWorker` triggers on schedule
+- [ ] Create unknown findings of varying ages and verify `UnknownsDecayService` reduces scores proportionally to age
+- [ ] Verify exponential decay: confirm older findings decay faster than newer ones
+- [ ] Verify age threshold: findings below the threshold are not decayed
+- [ ] Verify metrics are emitted during decay processing via `UnknownsDecayMetrics`