Start the progress reporter once per snapshot, not once per path (closes #253)

A backup without --cron of a snapshot with two or more paths panicked
with "close of closed channel". Scan runs once per path, and it started
the progress reporter and deferred its Stop each time; Stop closes the
reporter's signal channel, so the second path's Stop panicked.
scanAllDirectories now starts the reporter before the first path and
stops it after the last, and Scan no longer starts or stops it. A new
test backs up a two-path snapshot with the reporter on and restores
both paths.

Model: opus-5-5

TODO.md

@@ -22,6 +22,14 @@ the tag exists and is exercised; what is left is merging `next` to
 
 # Completed Steps
 
+- 2026-10-06: Made a backup without `--cron` of a snapshot with two or
+  more `paths` complete instead of panicking with `close of closed
+  channel` ([issue #253](https://git.eeqj.de/sneak/vaultik/issues/253)).
+  `Scan` runs once per path and started and stopped the progress
+  reporter each time, and a second stop panics. The reporter is now
+  started and stopped once per snapshot, around the scans of all its
+  paths.
+
 - 2026-10-06: Made a restore path argument select only that path and
   what is beneath it
   ([issue #223](https://git.eeqj.de/sneak/vaultik/issues/223)). The

internal/snapshot/scanner.go

@@ -224,12 +224,6 @@ func (s *Scanner) Scan(
 		log.Debug("No storage configured, blobs will not be uploaded")
 	}
 
-	// Start progress reporting if enabled
-	if s.progress != nil {
-		s.progress.Start()
-		defer s.progress.Stop()
-	}
-
 	// Phase 0: Repair any state left by an interrupted previous run, then
 	// load known files and chunks from the database into memory for fast
 	// lookup.
@@ -300,7 +294,9 @@ func (s *Scanner) Scan(
 	return result, nil
 }
 
-// GetProgress returns the progress reporter for this scanner
+// GetProgress returns the progress reporter for this scanner, or nil when
+// progress is off. Scan neither starts nor stops it: the caller does,
+// once for all the paths it scans, because a second Stop panics.
 func (s *Scanner) GetProgress() *ProgressReporter {
 	return s.progress
 }

internal/vaultik/snapshot.go

@@ -281,6 +281,11 @@ func (v *Vaultik) resolveSnapshotPaths(snapName string) ([]string, error) {
 func (v *Vaultik) scanAllDirectories(
 	scanner *snapshot.Scanner, resolvedDirs []string, snapshotID string,
 ) (*snapshotStats, error) {
+	if progress := scanner.GetProgress(); progress != nil {
+		progress.Start()
+		defer progress.Stop()
+	}
+
 	stats := &snapshotStats{}
 
 	for i, dir := range resolvedDirs {

internal/vaultik/two_path_snapshot_test.go

@@ -0,0 +1,71 @@
+package vaultik_test
+
+import (
+	"context"
+	"maps"
+	"path/filepath"
+	"testing"
+
+	"github.com/spf13/afero"
+	"github.com/stretchr/testify/require"
+	"sneak.berlin/go/vaultik/internal/config"
+	"sneak.berlin/go/vaultik/internal/database"
+	"sneak.berlin/go/vaultik/internal/log"
+	"sneak.berlin/go/vaultik/internal/storage"
+	"sneak.berlin/go/vaultik/internal/vaultik"
+)
+
+// A backup without --cron runs the progress reporter while one scanner
+// scans each path of the snapshot in turn. See
+// https://git.eeqj.de/sneak/vaultik/issues/253.
+//
+//nolint:paralleltest // installs the global logger via log.Initialize
+func TestBackupWithoutCronOfTwoPathSnapshotRestoresBothPaths(t *testing.T) {
+	log.Initialize(log.Config{})
+
+	const snapshotName = "data"
+
+	fs := afero.NewOsFs()
+	tempDir := t.TempDir()
+	firstDir := filepath.Join(tempDir, "first")
+	secondDir := filepath.Join(tempDir, "second")
+	storeDir := filepath.Join(tempDir, "remote")
+	restoreDir := filepath.Join(tempDir, "restored")
+	dbPath := filepath.Join(tempDir, "index.sqlite")
+
+	ctx := context.Background()
+	files := writeFaultSourceTree(t, fs, firstDir)
+	maps.Copy(files, writeFaultSourceTree(t, fs, secondDir))
+
+	cfg := faultTestConfig()
+	cfg.IndexPath = dbPath
+	cfg.ChunkSize = config.Size(faultChunkSize)
+	cfg.Snapshots = map[string]config.SnapshotConfig{
+		snapshotName: {Paths: []string{firstDir, secondDir}},
+	}
+
+	store, err := storage.NewFileStorer(storeDir)
+	require.NoError(t, err)
+
+	db, err := database.New(ctx, dbPath)
+	require.NoError(t, err)
+
+	repos := database.NewRepositories(db)
+	v := newBackupVaultik(ctx, cfg, store, repos, db, fs)
+
+	require.NoError(t, v.CreateSnapshot(&vaultik.SnapshotCreateOptions{
+		Snapshots: []string{snapshotName},
+	}))
+
+	id := localSnapshotID(ctx, t, repos, snapshotName)
+	require.NoError(t, db.Close())
+
+	reader := newReaderVaultik(ctx, cfg, store, nil, fs)
+	require.NoError(t, reader.Restore(&vaultik.RestoreOptions{
+		SnapshotID: id,
+		TargetDir:  restoreDir,
+		Verify:     true,
+	}))
+
+	assertRestoredTree(t, fs, restoreDir, files)
+}