feat(simulator): Grafana monitoring over generated Parquet

Monitoring compose profile: dependency-free Prometheus exporter that
scans the Parquet output with DuckDB (rows, detections, pose frames,
battery, RSSI, link distance, bytes on disk), Prometheus scrape config
and a provisioned Grafana dashboard. Demonstrates the observability
doctrine: fleet statistics derived from the data platform itself.

simulator/README.md

@@ -50,6 +50,21 @@ print(con.sql("""
 EOF
 ```
 
+## Monitoring: Grafana over the generated data
+
+The `monitoring` profile spins up a small metrics chain — a DuckDB-based exporter that scans the generated Parquet every few seconds, Prometheus, and a pre-provisioned Grafana dashboard:
+
+```bash
+docker compose --profile monitoring up -d          # exporter + prometheus + grafana
+# generate some flights in parallel or beforehand:
+FLIGHT_ID=$(date -u +%Y%m%dT%H%MZ)-sim docker compose up --scale drone=5
+```
+
+- Grafana: `http://localhost:3000` (anonymous admin — demo only) → dashboard **Swarm Fleet — generated data**
+- Prometheus: `http://localhost:9090` · exporter: `http://localhost:9105/metrics`
+
+Panels: telemetry rows by drone/sensor, detections by class, pose frames sent/received, battery per drone, RSSI and estimated distance per link, Parquet bytes/files on disk. The exporter is deliberately a demonstration of the observability doctrine from [07 — Observability](../docs/07-observability.md): fleet statistics are *derived from the data platform itself* — no agent on the drone, just SQL over the same Parquet everyone else reads.
+
 ## Reproducibility
 
 Every run is deterministic per `(SEED, DRONE_ID)`: same route jitter, same sensor noise, same detection sequence. A bug report is a seed and a config, not a description.