fix: backup labels to backup-bot-two v2 volume syntax (restore was a no-op)

backup-bot-two 2.4.0 snapshots paths INSIDE named volumes
(backupbot.backup.volumes.<vol>.path, relative to the volume root) and
IGNORES the old backupbot.backup.path label. The db pre-hook wrote
/postgres.dump.gz to the container's ephemeral root fs — outside every
volume — so the dump never reached the snapshot and the restore post-hook
failed on a missing file (gzip: /postgres.dump.gz: No such file).

- db: dump into the db-data volume (transient; hooks remove it) and
  snapshot only that file via backupbot.backup.volumes.db-data.path —
  same pattern as keycloak, which passes backup/restore on this CI.
  Also use $POSTGRES_DB in the restore hook: the previous $PLAUSIBLE_DB
  is defined nowhere and only connected via libpq's username fallback.
- clickhouse: snapshot only backup/events (the clickhouse-backup output)
  inside the event-data volume instead of the whole volume — restoring
  raw data files under a running server is unsafe; the post-hook performs
  the logical restore.

compose.yml

@@ -54,11 +54,15 @@ services:
     deploy:
       labels:
         backupbot.backup: "true"
-        backupbot.backup.pre-hook: sh -c 'pg_dump -U "$$POSTGRES_USER" -Fc "$$POSTGRES_DB" | gzip > "/postgres.dump.gz"'
-        backupbot.backup.path: "/postgres.dump.gz"
-        backupbot.backup.post-hook: "rm -f /postgres.dump.gz"
+        # backup-bot-two v2 snapshots paths INSIDE named volumes (backupbot.backup.volumes.<vol>.path,
+        # relative to the volume root) and ignores the old `backupbot.backup.path` label — a dump
+        # written to the container root fs never reaches the snapshot, so restore finds nothing.
+        # The dump therefore lives (transiently — the hooks remove it) at the db-data volume root.
+        backupbot.backup.volumes.db-data.path: "postgres.dump.gz"
+        backupbot.backup.pre-hook: sh -c 'pg_dump -U "$$POSTGRES_USER" -Fc "$$POSTGRES_DB" | gzip > /var/lib/postgresql/data/postgres.dump.gz'
+        backupbot.backup.post-hook: "rm -f /var/lib/postgresql/data/postgres.dump.gz"
         backupbot.restore: "true"
-        backupbot.restore.post-hook: sh -c 'gzip -d /postgres.dump.gz && pg_restore --clean -U "$$POSTGRES_USER" --dbname="$$PLAUSIBLE_DB" < /postgres.dump && rm -f /postgres.dump'
+        backupbot.restore.post-hook: sh -c 'gzip -d /var/lib/postgresql/data/postgres.dump.gz && pg_restore --clean -U "$$POSTGRES_USER" --dbname="$$POSTGRES_DB" < /var/lib/postgresql/data/postgres.dump && rm -f /var/lib/postgresql/data/postgres.dump'
 
   plausible_events_db:
     image: clickhouse/clickhouse-server:23.4.2.11-alpine
@@ -78,8 +82,11 @@ services:
     deploy:
       labels:
         backupbot.backup: "true"
+        # v2 volumes-include syntax (see db service): snapshot only the clickhouse-backup output
+        # inside the event-data volume — not the live raw data files (restoring those under a
+        # running server is unsafe; the restore post-hook performs the logical restore instead).
+        backupbot.backup.volumes.event-data.path: "backup/events"
         backupbot.backup.pre-hook: clickhouse-backup create events
-        backupbot.backup.path: "/var/lib/clickhouse/backup/events"
         backupbot.backup.post-hook: "rm -rf /var/lib/clickhouse/backup/events"
         backupbot.restore: "true"
         backupbot.restore.post-hook: clickhouse-backup restore --rm events && rm -rf /var/lib/clickhouse/backup/events