v0.15.1: Backup page Részletek overhaul with per-drive tier sections

Replace Tároló section with collapsible Részletek containing 3 tiers:
- Tier 1: per-drive restic repo stats with storage labels
- Tier 2: cross-drive items grouped by destination, split by method
- Tier 3: remote backup placeholder
Restore UI now shows tier + drive labels in snapshot dropdown.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

controller/internal/backup/restic.go

@@ -36,11 +36,13 @@ type SnapshotResult struct {
 
 // SnapshotInfo holds information about a restic snapshot.
 type SnapshotInfo struct {
-	ID       string    `json:"short_id"`
-	Time     time.Time `json:"time"`
-	Paths    []string  `json:"paths"`
-	Tags     []string  `json:"tags"`
-	RepoPath string    `json:"-"` // set by caller for multi-repo aggregation
+	ID         string    `json:"short_id"`
+	Time       time.Time `json:"time"`
+	Paths      []string  `json:"paths"`
+	Tags       []string  `json:"tags"`
+	RepoPath   string    `json:"-"`            // set by caller for multi-repo aggregation
+	Tier       int       `json:"tier"`         // 1 = primary, 2 = secondary
+	DriveLabel string    `json:"drive_label"`  // filled by caller from settings
 }
 
 // RepoStats holds repository statistics.