feat: consolidate analytics service with PII sanitization facade

[bellabuks]

Summary

The repo had two separate analytics paths (src/analytics and src/analytics-system) with different privacy assumptions. Events could be stored or sent externally without a single redaction policy.

Changes

• Added sanitizeMetadata() as a public facade method on AnalyticsService — strips known PII fields (�mail, password, ip, ipAddress, phone, �ddress, ssn, creditCard, oken, secret, �piKey) before any persistence or fan-out
• rack() now sanitizes metadata before saving, ensuring both the DB record and any downstream consumers receive clean data
• Updated �nalytics.service.spec.ts with tests covering: PII stripping, undefined metadata handling, persistence verification, and provider failure isolation

closes #21

[MaryammAli]

LGTM
Thank you for your contribution