FRE-4529: Transfer ShieldAI code from FrenoCorp repo

Transferred ShieldAI-related files mistakenly placed in ~/code/FrenoCorp:
- Services: spamshield (feature-flags, audit-logger, error-handler), voiceprint (config, service, feature-flags), darkwatch (pipeline, scan, scheduler, watchlist, webhook)
- Packages: shared-analytics, shared-auth, shared-ui, shared-utils (new); shared-billing, jobs supplemented with unique FC files
- Server: alerts (FC version newer), routes (spamshield, darkwatch, voiceprint)
- Config: turbo.json, tsconfig.base.json, vite/vitest configs, drizzle, Dockerfile
- VoicePrint ML service
- Examples

Pending: apps/{api,web,mobile}/ structured merge, shared-db/db mapping

Co-Authored-By: Paperclip <noreply@paperclip.ing>

packages/shared-analytics/src/services/mixpanel.service.ts

@@ -0,0 +1,117 @@
+import { Analytics } from '@segment/analytics-node';
+import { analyticsEnv, EventType, eventPropertiesSchema } from '../config/analytics.config';
+import { hashPhoneNumber } from '../utils/phone-hash';
+
+// Mixpanel service
+export class MixpanelService {
+  private client: Analytics;
+
+  constructor() {
+    this.client = new Analytics({
+      apiKey: analyticsEnv.MIXPANEL_TOKEN,
+    });
+  }
+
+  /**
+   * Track an event in Mixpanel
+   */
+  async track(
+    event: EventType,
+    distinctId: string,
+    properties?: Record<string, any>
+  ): Promise<void> {
+    const validatedProperties = eventPropertiesSchema.parse(properties);
+    
+    this.client.track({
+      event,
+      distinctId,
+      properties: {
+        ...validatedProperties,
+        ...properties,
+      },
+    });
+  }
+
+  /**
+   * Identify a user
+   */
+  async identify(userId: string, traits?: Record<string, any>): Promise<void> {
+    this.client.identify({
+      distinctId: userId,
+      traits,
+    });
+  }
+
+  /**
+   * Group users by subscription tier
+   */
+  async group(groupId: string, groupKey: string, traits?: Record<string, any>): Promise<void> {
+    this.client.group({
+      groupKey,
+      groupId,
+      traits,
+    });
+  }
+
+  /**
+   * Track user sign-up
+   */
+  async userSignedUp(userId: string, plan?: string, referrer?: string): Promise<void> {
+    await this.track(EventType.USER_SIGNED_UP, userId, {
+      plan,
+      referrer,
+      timestamp: new Date(),
+    });
+  }
+
+  /**
+   * Track subscription upgrade
+   */
+  async userUpgraded(userId: string, fromTier: string, toTier: string, mrr: number): Promise<void> {
+    await this.track(EventType.USER_UPGRADED, userId, {
+      fromTier,
+      toTier,
+      mrr,
+      timestamp: new Date(),
+    });
+  }
+
+  /**
+   * Track exposure detection
+   */
+  async exposureDetected(
+    userId: string,
+    exposureType: string,
+    severity: string,
+    source: string
+  ): Promise<void> {
+    await this.track(EventType.EXPOSURE_DETECTED, userId, {
+      exposureType,
+      severity,
+      source,
+      timestamp: new Date(),
+    });
+  }
+
+  /**
+   * Track spam detection
+   */
+  async spamBlocked(userId: string, phoneNumber: string, confidence: number, method: string): Promise<void> {
+    await this.track(EventType.SPAM_BLOCKED, userId, {
+      phoneNumber: hashPhoneNumber(phoneNumber),
+      confidence,
+      method,
+      timestamp: new Date(),
+    });
+  }
+
+  /**
+   * Flush pending events
+   */
+  async flush(): Promise<void> {
+    await this.client.flush();
+  }
+}
+
+// Export instance
+export const mixpanelService = new MixpanelService();