docs: add missing alerts, snapshot methods, and cross-links

- prometheus-monitoring: add 2 missing alert definitions
  (DBLabMetricsStale, DBLabSyncDown)
- create-snapshot: add pool-based snapshot creation method alongside
  existing clone-based method
- branching/index: add link to Coolify preview environments guide

https://claude.ai/code/session_011sPDgBjzL2N2X6jiYyoTjQ

Author: claude

docs/database-lab/prometheus-monitoring.md

@@ -202,6 +202,32 @@ dblab_sync_wal_lag_seconds
     description: "DBLab sync instance WAL replay is {{ $value | humanizeDuration }} behind"
 ```
 
+### Metrics collection stale alert
+
+```yaml
+- alert: DBLabMetricsStale
+  expr: time() - dblab_scrape_success_timestamp > 300
+  for: 5m
+  labels:
+    severity: warning
+  annotations:
+    summary: "DBLab metrics collection is stale"
+    description: "DBLab metrics have not been updated for more than 5 minutes"
+```
+
+### Sync instance down alert (physical mode)
+
+```yaml
+- alert: DBLabSyncDown
+  expr: dblab_sync_status{status="down"} == 1 or dblab_sync_status{status="error"} == 1
+  for: 5m
+  labels:
+    severity: critical
+  annotations:
+    summary: "DBLab sync instance is down"
+    description: "DBLab sync instance is not healthy"
+```
+
 ## OpenTelemetry integration
 
 DBLab metrics can be exported to OpenTelemetry-compatible backends using the OpenTelemetry Collector. This allows you to send metrics to Grafana Cloud, Datadog, New Relic, and other observability platforms.

docs/dblab-howtos/branching/index.md

@@ -7,4 +7,5 @@ slug: /dblab-howtos/branching
 ## Guides
 
 - [How to create a database branch](/docs/dblab-howtos/branching/create-branch)
-- [How to delete a database branch](/docs/dblab-howtos/branching/delete-branch)
+- [How to delete a database branch](/docs/dblab-howtos/branching/delete-branch)
+- [Preview environments with DBLab and Coolify](/docs/dblab-howtos/branching/preview-environments-with-dblab-and-coolify)

docs/dblab-howtos/snapshots/create-snapshot.md

@@ -27,12 +27,23 @@ Before you run any commands, install Database Lab CLI and initialize configurati
 - Command [`dblab snapshot`](/docs/reference-guides/dblab-client-cli-reference#command-snapshot)
 - Command [`dblab commit`](/docs/reference-guides/dblab-client-cli-reference#command-commit)
 
-### Create a snapshot
-Create a snapshot using the `dblab commit` command and specify the clone ID and message (optional):
+### Create a snapshot from a clone
+Create a snapshot from an existing clone using the `dblab commit` command:
 ```bash
 $ dblab commit --clone-id CLONE_ID --message "Snapshot message"
 ```
 
+### Create a snapshot from the current pool state
+You can also create a snapshot directly from the current state of a pool (without an existing clone):
+```bash
+$ dblab snapshot create
+```
+
+To specify a particular pool:
+```bash
+$ dblab snapshot create --pool POOL_NAME
+```
+
 Command `dblab snapshot list` shows all snapshots, including the one just created:
 ```bash
 $ dblab snapshot list