fix(deploy): reject destructive per-file pruning before apply

Reviewed-on: https://gitea.forust.xyz/forust/homelab/pulls/91

.gitea/workflows/deploy-lib.sh

@@ -31,6 +31,16 @@ warn() {
   echo "WARNING: $*" >&2
 }
 
+# Prune needs the complete desired set in one invocation. Per-file pruning
+# treats resources from the other files as absent and can delete them.
+check_prune_mode() {
+  if [ "$APPLY_PRUNE" = "true" ]; then
+    echo "ERROR: APPLY_PRUNE=true is unsupported by the per-file deploy loop." >&2
+    echo "Disable it; remove obsolete resources explicitly after review." >&2
+    return 1
+  fi
+}
+
 collect_k8s() {
   git -C "$REPO" ls-files -- "$1" \
     | grep -E '\.ya?ml$' \
@@ -720,6 +730,7 @@ check_referenced_secrets() {
 }
 
 stage_validate() {
+  check_prune_mode || return 1
   cd "$REPO"
   select_manifests
   local m k cf
@@ -753,18 +764,16 @@ stage_validate() {
 }
 
 stage_apply_k8s() {
+  check_prune_mode || return 1
   cd "$REPO"
   select_manifests >/dev/null
-  local ns_files=() other_files=() m k prune_opts=()
+  local ns_files=() other_files=() m k
   for m in ${K8S_MANIFESTS[@]+"${K8S_MANIFESTS[@]}"}; do
     case "$m" in
       */namespace.y?ml) ns_files+=("$m") ;;
       *) other_files+=("$m") ;;
     esac
   done
-  if [ "$APPLY_PRUNE" = "true" ]; then
-    prune_opts=(--prune -l app.kubernetes.io/managed-by=homelab-deploy)
-  fi
 
   # Record what is about to change, and publish it for the verify job, before
   # the first apply. Both are fatal on failure: see snapshot_dir.
@@ -789,7 +798,7 @@ stage_apply_k8s() {
   if [ "${#other_files[@]}" -gt 0 ]; then
     log "Applying resources (${#other_files[@]} files, our images pinned to digests)"
     for m in "${other_files[@]}"; do
-      if ! render_pinned <"$m" | kubectl apply "${prune_opts[@]}" -f -; then
+      if ! render_pinned <"$m" | kubectl apply -f -; then
         echo "ERROR: apply failed for ${m#"$REPO"/}" >&2
         exit 1
       fi