feat(grafana): starter dashboards for host/system, Loki logs, and observability self-monitoring

llm-fleet.json already owns LLM capacity+spec-decode. These three cover the
domains that had NO dashboard:
- host-system: node_exporter CPU/Load/Mem/Disk/Net/Uptime/FS/FDs for both
  Dankclaw and Dankserver (templated by job node-dankclaw|node-dankserver)
- logs-overview: Loki volume + per-container error rate + a sample log panel;
  container is parsed from the JSON line at query time (journal streams have
  no container_name stream label)
- observability: the stack's own health - Prometheus target up/down + scrape
  interval drift + samples/s + TSDB, Loki ingest/discard, Grafana CPU/mem.

Panel queries verified live against Prometheus/Loki; provisioned dashboards
confirmed via /api/search. Alertmanager is running but NOT scraped by
Prometheus - noted in the dashboard, no empty panels built on it.

shared/grafana/provisioning/dashboards/host-system.json

@@ -0,0 +1,144 @@
+{
+  "uid": "host-system",
+  "title": "Hosts \u2014 Dankclaw & Dankserver",
+  "description": "node_exporter for both servers. Starter set \u2014 throw-at-the-wall breadth; refine the windows and drop the noise. The picker selects the host; CPU/load/memory/filesystem/network are per-node.",
+  "tags": ["host", "system"],
+  "timezone": "browser",
+  "schemaVersion": 39,
+  "refresh": "30s",
+  "time": { "from": "now-6h", "to": "now" },
+  "templating": {
+    "list": [
+      {
+        "name": "node",
+        "label": "host",
+        "type": "query",
+        "datasource": { "type": "prometheus", "uid": "prometheus" },
+        "query": { "query": "label_values(up{job=~\"node-.*\"}, job)", "refId": "A" },
+        "includeAll": true,
+        "multi": true,
+        "current": { "text": "All", "value": "$__all" }
+      }
+    ]
+  },
+  "panels": [
+    {
+      "id": 1, "type": "stat", "title": "Uptime",
+      "description": "Time since boot. A drop means a reboot.",
+      "gridPos": { "h": 4, "w": 6, "x": 0, "y": 0 },
+      "datasource": { "type": "prometheus", "uid": "prometheus" },
+      "fieldConfig": { "defaults": { "unit": "s" }, "overrides": [] },
+      "targets": [{ "expr": "time() - node_boot_time_seconds{job=~\"$node\"}", "legendFormat": "{{job}}", "refId": "A" }]
+    },
+    {
+      "id": 2, "type": "stat", "title": "Memory used",
+      "description": "1 - MemAvailable/MemTotal. The honest \"in use\" figure (excludes reclaimable cache).",
+      "gridPos": { "h": 4, "w": 6, "x": 6, "y": 0 },
+      "datasource": { "type": "prometheus", "uid": "prometheus" },
+      "fieldConfig": { "defaults": { "unit": "percentunit", "min": 0, "max": 1, "thresholds": { "mode": "absolute", "steps": [{ "color": "green", "value": null }, { "color": "yellow", "value": 0.8 }, { "color": "red", "value": 0.92 }] } }, "overrides": [] },
+      "targets": [{ "expr": "1 - node_memory_MemAvailable_bytes{job=~\"$node\"} / node_memory_MemTotal_bytes{job=~\"$node\"}", "legendFormat": "{{job}}", "refId": "A" }]
+    },
+    {
+      "id": 3, "type": "stat", "title": "Load 5m / core",
+      "description": "Per-core load5. >1 sustained means runnable tasks are queuing behind cores.",
+      "gridPos": { "h": 4, "w": 6, "x": 12, "y": 0 },
+      "datasource": { "type": "prometheus", "uid": "prometheus" },
+      "fieldConfig": { "defaults": { "unit": "short", "thresholds": { "mode": "absolute", "steps": [{ "color": "green", "value": null }, { "color": "yellow", "value": 0.7 }, { "color": "red", "value": 1 }] } }, "overrides": [] },
+      "targets": [{ "expr": "node_load5{job=~\"$node\"} / count by (job) (node_cpu_seconds_total{job=~\"$node\",mode=\"idle\"})", "legendFormat": "{{job}}", "refId": "A" }]
+    },
+    {
+      "id": 4, "type": "stat", "title": "Open file handles",
+      "description": "FDs allocated vs the kernel maximum. Rising toward the max precedes EMFILE across the host.",
+      "gridPos": { "h": 4, "w": 6, "x": 18, "y": 0 },
+      "datasource": { "type": "prometheus", "uid": "prometheus" },
+      "fieldConfig": { "defaults": { "unit": "percentunit", "max": 1, "thresholds": { "mode": "absolute", "steps": [{ "color": "green", "value": null }, { "color": "yellow", "value": 0.7 }, { "color": "red", "value": 0.9 }] } }, "overrides": [] },
+      "targets": [{ "expr": "node_filefd_allocated{job=~\"$node\"} / node_filefd_maximum{job=~\"$node\"}", "legendFormat": "{{job}}", "refId": "A" }]
+    },
+    {
+      "id": 5, "type": "timeseries", "title": "CPU busy %",
+      "description": "CPU seconds/s in each mode = cores busy per mode; the stack sums to total cores in use (16/host here). A user or system spike points at what is loading the box; steal > 0 means the hypervisor is throttling.",
+      "gridPos": { "h": 8, "w": 12, "x": 0, "y": 4 },
+      "datasource": { "type": "prometheus", "uid": "prometheus" },
+      "fieldConfig": { "defaults": { "unit": "short", "min": 0, "custom": { "fillOpacity": 10, "lineWidth": 1, "stacking": { "mode": "normal" } } }, "overrides": [] },
+      "targets": [
+        { "expr": "sum by (job,mode) (rate(node_cpu_seconds_total{job=~\"$node\",mode!=\"idle\",mode!=\"iowait\"}[5m]))", "legendFormat": "{{job}} {{mode}}", "refId": "A" }
+      ]
+    },
+    {
+      "id": 6, "type": "timeseries", "title": "Load average",
+      "description": "load1/5/15 per host.",
+      "gridPos": { "h": 8, "w": 12, "x": 12, "y": 4 },
+      "datasource": { "type": "prometheus", "uid": "prometheus" },
+      "fieldConfig": { "defaults": { "unit": "short" }, "overrides": [] },
+      "targets": [
+        { "expr": "node_load1{job=~\"$node\"}", "legendFormat": "{{job}} load1", "refId": "A" },
+        { "expr": "node_load5{job=~\"$node\"}", "legendFormat": "{{job}} load5", "refId": "B" },
+        { "expr": "node_load15{job=~\"$node\"}", "legendFormat": "{{job}} load15", "refId": "C" }
+      ]
+    },
+    {
+      "id": 7, "type": "timeseries", "title": "Memory breakdown",
+      "description": "Total, free, buffers+cache. Reclaimable cache is not pressure; MemAvailable is the real headroom.",
+      "gridPos": { "h": 8, "w": 12, "x": 0, "y": 12 },
+      "datasource": { "type": "prometheus", "uid": "prometheus" },
+      "fieldConfig": { "defaults": { "unit": "bytes" }, "overrides": [] },
+      "targets": [
+        { "expr": "node_memory_MemTotal_bytes{job=~\"$node\"} - node_memory_MemAvailable_bytes{job=~\"$node\"}", "legendFormat": "{{job}} used", "refId": "A" },
+        { "expr": "node_memory_MemAvailable_bytes{job=~\"$node\"}", "legendFormat": "{{job}} available", "refId": "B" }
+      ]
+    },
+    {
+      "id": 8, "type": "timeseries", "title": "Filesystem free %",
+      "description": "Per mountpoint. The media/library stacks fill disks.",
+      "gridPos": { "h": 8, "w": 12, "x": 12, "y": 12 },
+      "datasource": { "type": "prometheus", "uid": "prometheus" },
+      "fieldConfig": { "defaults": { "unit": "percentunit", "min": 0, "max": 1, "thresholds": { "mode": "absolute", "steps": [{ "color": "red", "value": null }, { "color": "green", "value": 0.15 }] } }, "overrides": [] },
+      "targets": [
+        { "expr": "node_filesystem_avail_bytes{job=~\"$node\",fstype!~\"tmpfs|overlay|squashfs\"} / node_filesystem_size_bytes{job=~\"$node\",fstype!~\"tmpfs|overlay|squashfs\"}", "legendFormat": "{{job}} {{mountpoint}}", "refId": "A" }
+      ]
+    },
+    {
+      "id": 9, "type": "timeseries", "title": "Disk throughput",
+      "description": "Read/write bytes/s per device.",
+      "gridPos": { "h": 8, "w": 12, "x": 0, "y": 20 },
+      "datasource": { "type": "prometheus", "uid": "prometheus" },
+      "fieldConfig": { "defaults": { "unit": "Bps" }, "overrides": [] },
+      "targets": [
+        { "expr": "sum by (job,device) (rate(node_disk_read_bytes_total{job=~\"$node\"}[5m]))", "legendFormat": "{{job}} {{device}} R", "refId": "A" },
+        { "expr": "-sum by (job,device) (rate(node_disk_written_bytes_total{job=~\"$node\"}[5m]))", "legendFormat": "{{job}} {{device}} W", "refId": "B" }
+      ]
+    },
+    {
+      "id": 10, "type": "timeseries", "title": "Disk busy %",
+      "description": "Fraction of time the device had I/O in flight. Near 1 = the device is the bottleneck.",
+      "gridPos": { "h": 8, "w": 12, "x": 12, "y": 20 },
+      "datasource": { "type": "prometheus", "uid": "prometheus" },
+      "fieldConfig": { "defaults": { "unit": "percentunit", "min": 0, "max": 1 }, "overrides": [] },
+      "targets": [
+        { "expr": "rate(node_disk_io_time_seconds_total{job=~\"$node\"}[5m])", "legendFormat": "{{job}} {{device}}", "refId": "A" }
+      ]
+    },
+    {
+      "id": 11, "type": "timeseries", "title": "Network throughput",
+      "description": "Receive (up) / transmit (down) bytes/s per interface.",
+      "gridPos": { "h": 8, "w": 12, "x": 0, "y": 28 },
+      "datasource": { "type": "prometheus", "uid": "prometheus" },
+      "fieldConfig": { "defaults": { "unit": "Bps" }, "overrides": [] },
+      "targets": [
+        { "expr": "sum by (job,device) (rate(node_network_receive_bytes_total{job=~\"$node\",device!~\"lo|veth.*|br.*|docker.*\"}[5m]))", "legendFormat": "{{job}} {{device}} RX", "refId": "A" },
+        { "expr": "-sum by (job,device) (rate(node_network_transmit_bytes_total{job=~\"$node\",device!~\"lo|veth.*|br.*|docker.*\"}[5m]))", "legendFormat": "{{job}} {{device}} TX", "refId": "B" }
+      ]
+    },
+    {
+      "id": 12, "type": "timeseries", "title": "Network errors / drops",
+      "description": "Interface errors and drops \u2014 the signature of a saturated link or a bad NIC/cable.",
+      "gridPos": { "h": 8, "w": 12, "x": 12, "y": 28 },
+      "datasource": { "type": "prometheus", "uid": "prometheus" },
+      "fieldConfig": { "defaults": { "unit": "ops" }, "overrides": [] },
+      "targets": [
+        { "expr": "sum by (job,device) (rate(node_network_receive_errs_total{job=~\"$node\"}[5m]))", "legendFormat": "{{job}} {{device}} RX err", "refId": "A" },
+        { "expr": "sum by (job,device) (rate(node_network_transmit_errs_total{job=~\"$node\"}[5m]))", "legendFormat": "{{job}} {{device}} TX err", "refId": "B" }
+      ]
+    }
+  ]
+}

shared/grafana/provisioning/dashboards/logs-overview.json

@@ -0,0 +1,75 @@
+{
+  "uid": "logs-overview",
+  "title": "Logs \u2014 Loki (systemd journal)",
+  "description": "Everything in Loki arrives as the journal (job=systemd-journal); the container is a JSON field parsed at query time, not a stream label. Starter breadth \u2014 the volume/error panels group by the parsed container_name. Loki keeps ~7 days; wide ranges are cheap counts, not the raw log panel.",
+  "tags": ["logs", "loki"],
+  "timezone": "browser",
+  "schemaVersion": 39,
+  "refresh": "30s",
+  "time": { "from": "now-1h", "to": "now" },
+  "templating": {
+    "list": [
+      {
+        "name": "container",
+        "label": "container",
+        "type": "query",
+        "datasource": { "type": "loki", "uid": "loki" },
+        "query": { "query": "{job=\"systemd-journal\"} | json", "label": "container_name", "refId": "A" },
+        "includeAll": true,
+        "multi": true,
+        "refresh": 2,
+        "current": { "text": "All", "value": "$__all" }
+      }
+    ]
+  },
+  "panels": [
+    {
+      "id": 1, "type": "timeseries", "title": "Log volume by container (lines/s)",
+      "description": "Parse the journal JSON, count lines per container. Spikes = a chatty or crashing unit.",
+      "gridPos": { "h": 9, "w": 24, "x": 0, "y": 0 },
+      "datasource": { "type": "loki", "uid": "loki" },
+      "fieldConfig": { "defaults": { "unit": "reqps", "custom": { "fillOpacity": 20, "stacking": { "mode": "normal" } } }, "overrides": [] },
+      "targets": [{ "expr": "sum by (container_name) (count_over_time({job=\"systemd-journal\"} | json [$__auto]))", "legendFormat": "{{container_name}}", "refId": "A" }]
+    },
+    {
+      "id": 2, "type": "timeseries", "title": "Total log rate",
+      "description": "All journal lines per second.",
+      "gridPos": { "h": 8, "w": 12, "x": 0, "y": 9 },
+      "datasource": { "type": "loki", "uid": "loki" },
+      "fieldConfig": { "defaults": { "unit": "reqps" }, "overrides": [] },
+      "targets": [{ "expr": "sum(count_over_time({job=\"systemd-journal\"} [$__auto]))", "legendFormat": "all lines/s", "refId": "A" }]
+    },
+    {
+      "id": 3, "type": "timeseries", "title": "Error-level line rate",
+      "description": "Lines matching error/panic/fatal/fail. A blunt text match \u2014 the journal carries no structured level for all units.",
+      "gridPos": { "h": 8, "w": 12, "x": 12, "y": 9 },
+      "datasource": { "type": "loki", "uid": "loki" },
+      "fieldConfig": { "defaults": { "unit": "reqps", "color": { "mode": "fixed", "fixedColor": "red" } }, "overrides": [] },
+      "targets": [{ "expr": "sum(count_over_time({job=\"systemd-journal\"} |~ \"(?i)(error|panic|fatal|fail)\" [$__auto]))", "legendFormat": "error lines/s", "refId": "A" }]
+    },
+    {
+      "id": 4, "type": "timeseries", "title": "Errors by container",
+      "description": "Which unit is throwing. Rank by the top offenders.",
+      "gridPos": { "h": 8, "w": 12, "x": 0, "y": 17 },
+      "datasource": { "type": "loki", "uid": "loki" },
+      "fieldConfig": { "defaults": { "unit": "reqps" }, "overrides": [] },
+      "targets": [{ "expr": "sum by (container_name) (count_over_time({job=\"systemd-journal\"} |~ \"(?i)(error|panic|fatal)\" | json [$__auto]))", "legendFormat": "{{container_name}}", "refId": "A" }]
+    },
+    {
+      "id": 5, "type": "stat", "title": "Error lines (last 15m)",
+      "description": "Absolute count over the window, not a rate.",
+      "gridPos": { "h": 8, "w": 12, "x": 12, "y": 17 },
+      "datasource": { "type": "loki", "uid": "loki" },
+      "fieldConfig": { "defaults": { "unit": "short", "thresholds": { "mode": "absolute", "steps": [{ "color": "green", "value": null }, { "color": "yellow", "value": 50 }, { "color": "red", "value": 500 }] } }, "overrides": [] },
+      "targets": [{ "expr": "sum(count_over_time({job=\"systemd-journal\"} |~ \"(?i)(error|panic|fatal)\" [15m]))", "instant": true, "legendFormat": "errors/15m", "refId": "A" }]
+    },
+    {
+      "id": 6, "type": "logs", "title": "Journal (filtered)",
+      "description": "Raw lines for the selected containers. Set the container picker; keep the window tight.",
+      "gridPos": { "h": 12, "w": 24, "x": 0, "y": 25 },
+      "datasource": { "type": "loki", "uid": "loki" },
+      "options": { "showTime": true, "wrapLogMessage": true, "sortOrder": "Descending", "enableLogDetails": true },
+      "targets": [{ "expr": "{job=\"systemd-journal\"} | json | container_name=~\"$container\"", "refId": "A" }]
+    }
+  ]
+}

shared/grafana/provisioning/dashboards/observability.json

@@ -0,0 +1,96 @@
+{
+  "uid": "observability",
+  "title": "Observability \u2014 self-monitoring",
+  "description": "The health of the stack that watches the fleet: Prometheus scrape/TSDB, Loki ingest, Grafana. If this is red the dashboards lie. Note: Alertmanager is running but NOT scraped by Prometheus (no job) \u2014 its metrics are absent by design gap, not fault.",
+  "tags": ["observability", "meta"],
+  "timezone": "browser",
+  "schemaVersion": 39,
+  "refresh": "30s",
+  "time": { "from": "now-6h", "to": "now" },
+  "panels": [
+    {
+      "id": 1, "type": "stat", "title": "Targets up",
+      "gridPos": { "h": 4, "w": 4, "x": 0, "y": 0 },
+      "datasource": { "type": "prometheus", "uid": "prometheus" },
+      "fieldConfig": { "defaults": { "unit": "short", "thresholds": { "mode": "absolute", "steps": [{ "color": "green", "value": null }] } }, "overrides": [] },
+      "targets": [{ "expr": "count(up == 1)", "instant": true, "refId": "A" }]
+    },
+    {
+      "id": 2, "type": "stat", "title": "Targets down",
+      "description": "Known structural downs: comfyui (no metrics endpoint), gitea (metrics off), and the homepage 'services' probes. Real regressions ride up from here too \u2014 check the table before dismissing.",
+      "gridPos": { "h": 4, "w": 4, "x": 4, "y": 0 },
+      "datasource": { "type": "prometheus", "uid": "prometheus" },
+      "fieldConfig": { "defaults": { "unit": "short", "thresholds": { "mode": "absolute", "steps": [{ "color": "green", "value": null }, { "color": "red", "value": 1 }] } }, "overrides": [] },
+      "targets": [{ "expr": "count(up == 0)", "instant": true, "refId": "A" }]
+    },
+    {
+      "id": 3, "type": "stat", "title": "TSDB head series",
+      "description": "Active series in memory. A jump = a new exporter or a label-cardinality leak.",
+      "gridPos": { "h": 4, "w": 5, "x": 8, "y": 0 },
+      "datasource": { "type": "prometheus", "uid": "prometheus" },
+      "fieldConfig": { "defaults": { "unit": "short" }, "overrides": [] },
+      "targets": [{ "expr": "prometheus_tsdb_head_series", "instant": true, "refId": "A" }]
+    },
+    {
+      "id": 4, "type": "stat", "title": "Discovered targets",
+      "gridPos": { "h": 4, "w": 5, "x": 13, "y": 0 },
+      "datasource": { "type": "prometheus", "uid": "prometheus" },
+      "fieldConfig": { "defaults": { "unit": "short" }, "overrides": [] },
+      "targets": [{ "expr": "sum(prometheus_sd_discovered_targets)", "instant": true, "refId": "A" }]
+    },
+    {
+      "id": 5, "type": "stat", "title": "Prometheus mem",
+      "gridPos": { "h": 4, "w": 3, "x": 18, "y": 0 },
+      "datasource": { "type": "prometheus", "uid": "prometheus" },
+      "fieldConfig": { "defaults": { "unit": "bytes" }, "overrides": [] },
+      "targets": [{ "expr": "process_resident_memory_bytes{job=\"prometheus\"}", "instant": true, "refId": "A" }]
+    },
+    {
+      "id": 6, "type": "stat", "title": "Grafana up",
+      "gridPos": { "h": 4, "w": 3, "x": 21, "y": 0 },
+      "datasource": { "type": "prometheus", "uid": "prometheus" },
+      "fieldConfig": { "defaults": { "mappings": [{ "type": "value", "options": { "1": { "text": "UP", "color": "green" }, "0": { "text": "DOWN", "color": "red" } } }], "thresholds": { "mode": "absolute", "steps": [{ "color": "red", "value": null }, { "color": "green", "value": 1 }] } }, "overrides": [] },
+      "targets": [{ "expr": "up{job=\"grafana\"}", "instant": true, "refId": "A" }]
+    },
+    {
+      "id": 7, "type": "table", "title": "Target health",
+      "description": "Every scrape target and its current up. Sort by Value to surface regressions.",
+      "gridPos": { "h": 9, "w": 12, "x": 0, "y": 4 },
+      "datasource": { "type": "prometheus", "uid": "prometheus" },
+      "options": { "sortBy": [{ "displayName": "Value", "sortOrder": "Asc" }] },
+      "targets": [{ "expr": "up", "format": "table", "instant": true, "refId": "A" }]
+    },
+    {
+      "id": 8, "type": "timeseries", "title": "Scrape interval drift (p99 actual)",
+      "description": "Actual seconds between scrapes (summary quantile). Above the 15s scrape_interval = Prometheus is falling behind its own cadence (slow endpoints or overload).",
+      "gridPos": { "h": 9, "w": 12, "x": 12, "y": 4 },
+      "datasource": { "type": "prometheus", "uid": "prometheus" },
+      "fieldConfig": { "defaults": { "unit": "s" }, "overrides": [] },
+      "targets": [{ "expr": "prometheus_target_interval_length_seconds{quantile=\"0.99\"}", "legendFormat": "{{instance}}", "refId": "A" }]
+    },
+    {
+      "id": 9, "type": "timeseries", "title": "Scrape samples/s",
+      "description": "Total samples ingested across all jobs.",
+      "gridPos": { "h": 8, "w": 12, "x": 0, "y": 13 },
+      "datasource": { "type": "prometheus", "uid": "prometheus" },
+      "fieldConfig": { "defaults": { "unit": "short" }, "overrides": [] },
+      "targets": [{ "expr": "sum(rate(scrape_samples_scraped[5m]))", "legendFormat": "samples/s", "refId": "A" }]
+    },
+    {
+      "id": 10, "type": "timeseries", "title": "Loki request rate",
+      "description": "Loki served requests/s (push, query). A drop to zero means ingest or query has stopped.",
+      "gridPos": { "h": 8, "w": 12, "x": 12, "y": 13 },
+      "datasource": { "type": "prometheus", "uid": "prometheus" },
+      "fieldConfig": { "defaults": { "unit": "reqps" }, "overrides": [] },
+      "targets": [{ "expr": "sum by (route) (rate(loki_request_duration_seconds_count[5m]))", "legendFormat": "{{route}}", "refId": "A" }]
+    },
+    {
+      "id": 11, "type": "timeseries", "title": "Exporter process CPU",
+      "description": "CPU by monitored process \u2014 spot a runaway exporter or the Prometheus process itself.",
+      "gridPos": { "h": 8, "w": 24, "x": 0, "y": 21 },
+      "datasource": { "type": "prometheus", "uid": "prometheus" },
+      "fieldConfig": { "defaults": { "unit": "percentunit" }, "overrides": [] },
+      "targets": [{ "expr": "sum by (job) (rate(process_cpu_seconds_total[5m]))", "legendFormat": "{{job}}", "refId": "A" }]
+    }
+  ]
+}