v0.331.0: a removal deletes the volumes still labelled with the app's project that its definition no longer declares (R-1117)

compose down --volumes removes only the current definition's volumes; a volume a template dropped (or an older restore
re-created) survived 'remove with data' on 9202 (nextcloud_nextcloud_redis_data). Red-proofed.

controller/internal/stacks/r1117_leftover_volume_test.go

@@ -0,0 +1,78 @@
+package stacks
+
+import (
+	"sort"
+	"strings"
+	"sync"
+	"testing"
+)
+
+// R-1117: a template that drops a volume leaves the old one on an installed box, still carrying the app's compose project
+// label (and a restore re-creates it with that label). `compose down --volumes` removes only the volumes the CURRENT
+// definition declares, so before this fix the removal listed it and kept it — measured on scratch 9202, 2026-10-18:
+// Nextcloud removed „with data", `nextcloud_nextcloud_redis_data` still there. The consequence pinned: after the
+// removal no volume with the app's project label is left, and a volume of another project is never touched.
+// RED-PROOF: delete the leftover loop in RemoveStack → "left behind: [app_app_redis_data]".
+func TestR1117_RemoveDeletesALabelledVolumeTheDefinitionNoLongerDeclares(t *testing.T) {
+	drive := t.TempDir()
+	m, _, _ := newR442Manager(t, "app", ssdCompose, driveAppYAML(drive), drive)
+	var mu sync.Mutex
+	// project label per volume: the app's own (declared or not), and another app's.
+	vols := map[string]string{"app_app_redis_data": "app", "other_app_data": "other"}
+	var removedByRm []string
+	m.execFn = func(name string, args ...string) (string, error) {
+		mu.Lock()
+		defer mu.Unlock()
+		a := strings.Join(args, " ")
+		switch {
+		case strings.HasPrefix(a, "volume ls --filter label=com.docker.compose.project="):
+			p := strings.TrimPrefix(strings.Fields(a)[3], "label=com.docker.compose.project=")
+			var out []string
+			for v, proj := range vols {
+				if proj == p {
+					out = append(out, v)
+				}
+			}
+			sort.Strings(out)
+			return strings.Join(out, "\n"), nil
+		case a == "volume ls -q":
+			var out []string
+			for v := range vols {
+				out = append(out, v)
+			}
+			sort.Strings(out)
+			return strings.Join(out, "\n"), nil
+		case strings.HasPrefix(a, "volume rm "):
+			v := strings.Fields(a)[len(strings.Fields(a))-1]
+			delete(vols, v)
+			removedByRm = append(removedByRm, v)
+			return v, nil
+		}
+		return "", nil
+	}
+	resp, err := m.RemoveStack("app", false, nil)
+	if err != nil {
+		t.Fatalf("RemoveStack: %v", err)
+	}
+	mu.Lock()
+	defer mu.Unlock()
+	var left []string
+	for v, proj := range vols {
+		if proj == "app" {
+			left = append(left, v)
+		}
+	}
+	if len(left) > 0 {
+		t.Fatalf("left behind: %v — a volume with the app's project label outlived its removal", left)
+	}
+	if _, ok := vols["other_app_data"]; !ok {
+		t.Fatalf("another app's volume was removed (rm calls: %v)", removedByRm)
+	}
+	found := false
+	for _, v := range resp.VolumesRemoved {
+		found = found || v == "app_app_redis_data"
+	}
+	if !found {
+		t.Errorf("volumes_removed = %v, want it to name app_app_redis_data", resp.VolumesRemoved)
+	}
+}