v0.172.0 fixup 2: drop import/* from the carry-list

Found on the demo-hp live leg: with import, import/paperless and import/calibre
in the carry-list, the derived skeleton RE-CREATES a per-drive drop-zone on every
drive forever — the dead lookalike the canonical root exists to remove, and one
that is never backed up (class: excluded).

Not a zero-removals violation: nothing deletes what an existing box has. Both
demo boxes' old drop-zones were verified to hold zero files before the change.

controller/internal/appbackup/skeleton_determinism_test.go

@@ -4,6 +4,7 @@ import (
 	"os"
 	"path/filepath"
 	"slices"
+	"strings"
 	"testing"
 )
 
@@ -132,3 +133,31 @@ func TestEnsureUserdataSkeletonCreatesOnly(t *testing.T) {
 		t.Errorf("a pre-existing customer dir was removed — zero-removals violated: %v", err)
 	}
 }
+
+// R-75: a DATA drive must never get a per-drive drop-zone from the skeleton. Carrying the old
+// `import/*` entries would have the skeleton re-create a dead lookalike on every drive forever —
+// one that is also never backed up, since import paths are class: excluded.
+//
+// This is NOT a zero-removals violation: nothing deletes the dirs a box already has (see
+// TestEnsureUserdataSkeletonCreatesOnly). They stop being maintained and stop appearing on fresh boxes.
+func TestSkeletonNeverCreatesAPerDriveDropZone(t *testing.T) {
+	// The catalog no longer implies any ${USERDATA_PATH}/import path — the binds moved to
+	// ${IMPORT_PATH} — so the only way one could appear is via the carry-list.
+	for _, derived := range [][]string{nil, {"media/podcasts", "roms"}} {
+		for _, d := range BuildUserdataSkeleton(derived) {
+			if d == "import" || strings.HasPrefix(d, "import/") {
+				t.Errorf("derived=%v: skeleton created a per-drive drop-zone %q — the canonical root is on the SYSTEM drive", derived, d)
+			}
+		}
+	}
+	for _, c := range UserdataSkeletonCarry() {
+		if c == "import" || strings.HasPrefix(c, "import/") {
+			t.Errorf("the carry-list still holds %q", c)
+		}
+	}
+	// A catalog app that genuinely declares a ${USERDATA_PATH}/import/... bind would still be
+	// honoured — the rule is "don't carry them", not "filter them out".
+	if !slices.Contains(BuildUserdataSkeleton([]string{"import/valami"}), "import/valami") {
+		t.Error("a genuinely derived userdata import path must still be created")
+	}
+}

controller/internal/appbackup/userdata.go

@@ -57,20 +57,25 @@ func ImportDir(nsRoot string) string {
 //
 //   - `documents` is implied by NO catalog app (SPIKE P0(a)) yet exists on both demo boxes and is
 //     customer-visible — it may hold customer files. Derivation alone would drop it.
-//   - `import/paperless` and `import/calibre` moved to the canonical system-drive root in R-75, so
-//     derivation no longer implies them under a data drive either. The pre-existing ones stay put;
-//     nothing in this arc deletes a directory.
 //
 // It doubles as the fresh-box floor: on a box whose catalog has not synced yet the derived set is
 // empty, and the customer still gets the full standard tree instead of a nearly-empty one.
 //
+// DELIBERATELY ABSENT: `import`, `import/paperless`, `import/calibre`. They were in the v0.171.0
+// hardcoded list, and carrying them would have the skeleton RE-CREATE a per-drive drop-zone on every
+// drive forever — the exact dead-lookalike R-75 exists to remove, and one that is never backed up
+// (`class: excluded`). Zero-removals is about not DELETING what a box already has, not about
+// re-creating it on boxes that never had it: nothing here removes the pre-existing dirs on
+// demo-felhom / demo-hp, they simply stop being maintained and stop appearing on fresh boxes.
+// Verified before the change: both boxes' old drop-zones held ZERO files (2026-07-26). A box with
+// pending files in an old drop-zone would need an operator-run move — see REPORT.md.
+//
 // ASCII, no spaces (flows through ${} interpolation, shell, and the rsync merge walk).
 func UserdataSkeletonCarry() []string {
 	return []string{
 		"media", "media/movies", "media/tv", "media/music", "media/audiobooks",
 		"media/books", "media/comics", "media/photos",
 		"downloads",
-		"import", "import/paperless", "import/calibre",
 		"roms",
 		"documents",
 	}

controller/internal/appbackup/userdata_test.go

@@ -13,9 +13,12 @@ func TestSharedContentGID(t *testing.T) {
 	}
 }
 
-// TestUserdataSkeleton_List asserts the locked skeleton subdir set. R-75 renamed the hardcoded list
-// to UserdataSkeletonCarry (it is now the non-derived carry-list); the asserted set is UNCHANGED,
-// which is exactly the zero-removals promise.
+// TestUserdataSkeleton_List asserts the locked carry-list. R-75 renamed the hardcoded list to
+// UserdataSkeletonCarry (it is now the non-derived carry-list) and DELIBERATELY dropped the three
+// `import*` entries: carrying them would re-create a per-drive drop-zone on every drive forever, the
+// dead lookalike the canonical root exists to remove. That is not a removal — nothing deletes the
+// dirs an existing box has; they stop being maintained and stop appearing on fresh boxes. Every other
+// entry is unchanged, which is the zero-removals promise.
 func TestUserdataSkeleton_List(t *testing.T) {
 	got := map[string]bool{}
 	for _, s := range UserdataSkeletonCarry() {
@@ -23,13 +26,18 @@ func TestUserdataSkeleton_List(t *testing.T) {
 	}
 	for _, want := range []string{
 		"media/movies", "media/tv", "media/music", "media/audiobooks", "media/books",
-		"media/comics", "media/photos", "downloads", "import/paperless", "import/calibre",
+		"media/comics", "media/photos", "downloads",
 		"roms", "documents",
 	} {
 		if !got[want] {
 			t.Errorf("skeleton missing %q", want)
 		}
 	}
+	for _, gone := range []string{"import", "import/paperless", "import/calibre"} {
+		if got[gone] {
+			t.Errorf("carry-list must NOT hold %q — the drop-zone is canonical on the system drive (R-75)", gone)
+		}
+	}
 }
 
 // TestUserdataDir confirms the userdata root is a sibling under the namespace.