feat(error-tracking): add GlitchTip integration with shared error-tracking package

Infrastructure:
- Add GlitchTip (web + worker) to docker-compose.macmini.yml (port 8020)
- Add glitchtip.mana.how to Cloudflare Tunnel config
- Add glitchtip database to init-db SQL
- Add GLITCHTIP_DSN to .env.development

Shared Package (@manacore/shared-error-tracking):
- initErrorTracking() - Sentry-compatible init with GlitchTip DSN
- captureException(), captureMessage(), setUser(), setTag(), flush()
- SentryExceptionFilter for NestJS (captures 5xx errors only)
- Graceful no-op when DSN is not configured

Integration:
- Add instrument.ts to calendar, contacts, todo backends
- Import instrument.ts before app bootstrap in all 3 main.ts files
- Error tracking auto-initializes when GLITCHTIP_DSN env var is set

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.env.development

@@ -12,6 +12,11 @@
 # SHARED - Used across multiple apps
 # ============================================
 
+# GlitchTip Error Tracking (self-hosted Sentry-compatible)
+# Set DSN after creating projects in GlitchTip admin
+# Format: https://<key>@glitchtip.mana.how/<project-id>
+GLITCHTIP_DSN=
+
 # Mana Core Auth Service
 MANA_CORE_AUTH_URL=http://localhost:3001
 # Service key for bot-to-auth communication (Matrix-SSO-Link)