feat(observability): add local grafana+prom stack for metrics insights

observability/promtail/promtail.yaml

@@ -0,0 +1,30 @@
+server:
+  http_listen_port: 3102
+
+clients:
+  - url: http://loki:3100/loki/api/v1/push
+
+positions:
+  filename: /tmp/positions.yaml
+
+target_config:
+  sync_period: 10s
+
+scrape_configs:
+  - job_name: listory
+    journal:
+      labels:
+        job: listory
+    relabel_configs:
+      # services
+      - source_labels:
+          - __journal__systemd_unit
+        target_label: unit
+      # docker containers
+      - source_labels:
+          - __journal_container_name
+        target_label: container # use whatever label you like
+      - source_labels:
+          - container
+        action: keep
+        regex: listory-.* # only keep api logs