Fix SMS classifier test mock: add defaultScores and metadataLimits exports (FRE-4509)

The test mock for spamshield.config was missing defaultScores and
metadataLimits exports that are imported by spamshield.service.ts,
causing 8 tests to fail with 'No defaultScores export is defined'.

packages/api/src/__tests__/sms-classifier-race-condition.test.ts

@@ -35,6 +35,31 @@ vi.mock('../services/spamshield/spamshield.config', () => ({
     VERY_HIGH: 'very_high',
   },
   spamRateLimits: {},
+  defaultScores: {
+    defaultReputationConfidence: 0.0,
+    defaultReputationLowConfidence: 0.1,
+    defaultBaseConfidence: 0.5,
+    defaultMaxConfidence: 1.0,
+    featureWeights: {
+      urlPresent: 0.1,
+      highEmojiDensity: 0.15,
+      urgencyKeyword: 0.2,
+      excessiveCaps: 0.15,
+    },
+    defaultSpamScore: 0.0,
+    highReputationThreshold: 0.7,
+    reputationWeightInCombinedScore: 0.4,
+    shortDurationScore: 0.2,
+    voipScore: 0.15,
+    unusualHoursScore: 0.1,
+    hiyaWeightInCombinedScore: 0.7,
+    truecallerWeightInCombinedScore: 0.3,
+  },
+  metadataLimits: {
+    maxMetadataSizeBytes: 4096,
+    maxMetadataKeys: 20,
+    maxMetadataValueSizeBytes: 512,
+  },
 }));
 
 describe('SMSClassifierService', () => {