feat(grafana): add ActivityWatch Prometheus exporter and dashboards

- Add Python exporter for ActivityWatch API metrics collection
- Configure Prometheus to scrape ActivityWatch exporter
- Create Grafana dashboard for ActivityWatch overview
- Integrate ActivityWatch monitoring into existing docker-compose stack
- Add Prometheus datasource for ActivityWatch metrics

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Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

grafana-1c/grafana/provisioning/datasources/aw_prometheus.yml

@@ -0,0 +1,9 @@
+apiVersion: 1
+
+datasources:
+  - name: Prometheus
+    type: prometheus
+    access: proxy
+    url: http://prometheus:9090
+    isDefault: true
+    editable: true