feat: complete M0 — legal pages, consent, tip_views metrics, account deletion UI

- /legal/terms and /legal/privacy pages (linked from sign-in)
- Consent (consentGiven=true) recorded on first Google sign-in
- tip_views table: one row per tip served — enables activation + reaction rate queries
- tip_views purged on account deletion
- Delete account button on /connect (confirm → revoke tokens → purge data → sign out)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.playwright-mcp/page-2026-04-14T14-12-17-872Z.yml

@@ -0,0 +1,2 @@
+- main [ref=e2] [cursor=pointer]:
+  - generic [ref=e3]: ···