feat(ops): self-heal disk pressure instead of only alerting

The 5-minute disk probe now reclaims storage automatically: from 85% it runs the gentle age-windowed Docker prune, from 90% it drops the age windows (docker-prune.sh --force: all unused build cache and unreferenced images, all stopped containers) so a mount can never silently max out. Alerts still fire at 85/90/95% and their hint now points at non-Docker growth when reclaiming is not enough. Force mode is reserved for the worker; deploys keep the gentle mode. Volumes are off-limits in every path.

scripts/docker-prune.sh

@@ -1,15 +1,21 @@
 #!/usr/bin/env bash
 # Reclaim Docker's unused cache so host storage stays bounded.
 #
-# Safe scopes only, by design:
-#   - BuildKit cache older than 72h, hard-capped at 4 GB (Debian /pnpm store is
-#     shared across builds; everything newer than that speeds up rebuilds).
-#   - Images referenced by NO running/stopped container and older than 7 days
-#     (covers stale epicnext-cms sha tags, old mariadb/byparr pulls, etc.).
-#   - Containers stopped for more than 24h.
+# Modes:
+#   (default) — gentle, age-windowed (keeps rollback + rebuild speed):
+#     - BuildKit cache older than 72h, hard-capped at 4 GB (Debian /pnpm store
+#       is shared across builds; everything newer speeds up rebuilds).
+#     - Images referenced by NO container and older than 7 days.
+#     - Containers stopped for more than 24h.
+#   --force — emergency mode ("never let the disk max out"): drops every age
+#     window and reclaims all unused bytes Docker can free:
+#     - ALL unreferenced build cache,
+#     - ALL unreferenced images (no 7-day grace),
+#     - ALL stopped containers.
+#     Trade-off: waiting rebuilds re-fetch deps/images later.
 #
-# Volumes are NEVER pruned here: mariadb-turbo-data is a database. This script
-# is idempotent and exits 0 when Docker is unavailable.
+# Volumes are NEVER pruned in either mode: mariadb-turbo-data is a database.
+# Idempotent; exits 0 when Docker is unavailable.
 set -Eeuo pipefail
 DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
 LOG_DIR="${LOG_DIR:-$DIR/logs}"
@@ -17,17 +23,28 @@ mkdir -p "$LOG_DIR"
 LOG_FILE="$LOG_DIR/docker-prune.log"
 now() { date '+%Y-%m-%d %H:%M:%S'; }
 
+FORCE=0
+if [[ "${1:-}" == "--force" ]]; then
+  FORCE=1
+fi
+
 command -v docker >/dev/null 2>&1 || {
   printf '[%s] docker CLI unavailable; nothing to prune\n' "$(now)" >>"$LOG_FILE"
   exit 0
 }
 
-printf '\n[%s] === docker prune start ===\n' "$(now)" >>"$LOG_FILE"
+printf '\n[%s] === docker prune start%s ===\n' "$(now)" "$( (( FORCE )) && printf ' (FORCE)' )" >>"$LOG_FILE"
 docker system df >>"$LOG_FILE" 2>&1 || true
 
-docker builder prune -af --filter "until=72h" --max-used-space=4g >>"$LOG_FILE" 2>&1 || true
-docker image prune -af --filter "until=168h" >>"$LOG_FILE" 2>&1 || true
-docker container prune -f --filter "until=24h" >>"$LOG_FILE" 2>&1 || true
+if (( FORCE )); then
+  docker builder prune -af >>"$LOG_FILE" 2>&1 || true
+  docker image prune -af >>"$LOG_FILE" 2>&1 || true
+  docker container prune -f >>"$LOG_FILE" 2>&1 || true
+else
+  docker builder prune -af --filter "until=72h" --max-used-space=4g >>"$LOG_FILE" 2>&1 || true
+  docker image prune -af --filter "until=168h" >>"$LOG_FILE" 2>&1 || true
+  docker container prune -f --filter "until=24h" >>"$LOG_FILE" 2>&1 || true
+fi
 
-printf '\n[%s] === docker prune complete ===\n' "$(now)" >>"$LOG_FILE"
+printf '\n[%s] === docker prune complete%s ===\n' "$(now)" "$( (( FORCE )) && printf ' (FORCE)' )" >>"$LOG_FILE"
 docker system df >>"$LOG_FILE" 2>&1 || true