Observability Stack Setup

Set up an observability stack for:

**Application:** [APP_DESCRIPTION]
**Stack:** [TECH_STACK]
**Budget:** [BUDGET — e.g., "open-source only", "up to $100/mo", "enterprise tools OK"]

Generate:
1. **Structured logging** — JSON log format with correlation IDs, request context
2. **Metrics collection** — key metrics for each service (latency, error rate, saturation)
3. **Distributed tracing** — trace requests across service boundaries
4. **Dashboard templates** — Grafana/Datadog dashboards for the key metrics
5. **Alerting rules** — what to alert on, thresholds, and escalation policy
6. **Log aggregation** — centralized log search and filtering
7. **Implementation** — middleware/library code to instrument the application

Include the instrumentation code, dashboard JSON, and alert configurations.