fix(api): drop redundant avgNearMissDelta guard in loosen-threshold branch

bugbot LOW: nearMisses is filtered to s.score <= threshold + 0.03 so
avgNearMissDelta is constrained to (0, 0.03] by construction. The
extra '< 0.03' guard never excluded anything useful but did suppress
the loosen recommendation in the boundary case where every near miss
sits at exactly threshold + 0.03 (delta avg == 0.03), falling through
to 'optimal' despite a high near-miss rate.

Author: jamby77

apps/api/src/cache-proposals/cache-readonly.service.ts

@@ -222,7 +222,8 @@ export class CacheReadonlyService {
       recommendation = THRESHOLD_RECOMMENDATIONS.TIGHTEN;
       recommendedThreshold = Math.max(0, threshold - config.uncertainty_band * 1.5);
       reasoning = THRESHOLD_REASONINGS.tighten(uncertainHitRate);
-    } else if (nearMissRate > 0.3 && avgNearMissDelta < 0.03) {
+    } else if (nearMissRate > 0.3) {
+      // avgNearMissDelta is constrained to (0, 0.03] by the nearMisses filter.
       recommendation = THRESHOLD_RECOMMENDATIONS.LOOSEN;
       recommendedThreshold = threshold + avgNearMissDelta;
       reasoning = THRESHOLD_REASONINGS.loosen(nearMissRate);