v0.12.8: complete cross-drive backup + per-tier UI

- Cross-drive now copies DB dumps (_db/) and config (_config/) alongside user data
- restic cross-drive includes config dir + full DB dump dir
- UI: per-tier rows (1. mentés / 2. mentés) instead of per-layer (DB/Konfig/Data)
- UI: BackupContents label shows what each tier protects (DB + Konfig + Adatok)
- UI: rsync backups show browsable indicator (📁)
- Cleanup: removed unused filterSnapshotsByPaths + pathCovers from router.go

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

controller/internal/api/router.go

@@ -469,33 +469,6 @@ func (r *Router) backupSnapshots(w http.ResponseWriter, req *http.Request) {
 	writeJSON(w, http.StatusOK, apiResponse{OK: true, Data: snapshots})
 }
 
-// filterSnapshotsByPaths returns only snapshots whose Paths overlap with requiredPaths.
-// A snapshot matches if any of its paths is a prefix of (or prefixed by) any required path.
-// M10: Uses separator-aware prefix check to prevent /mnt/hdd_1 matching /mnt/hdd_10/data.
-func filterSnapshotsByPaths(snapshots []backup.SnapshotInfo, requiredPaths []string) []backup.SnapshotInfo {
-	var filtered []backup.SnapshotInfo
-outer:
-	for _, snap := range snapshots {
-		for _, required := range requiredPaths {
-			for _, sp := range snap.Paths {
-				if pathCovers(required, sp) || pathCovers(sp, required) {
-					filtered = append(filtered, snap)
-					continue outer
-				}
-			}
-		}
-	}
-	return filtered
-}
-
-// pathCovers returns true if base is equal to or a directory-prefix of target.
-func pathCovers(base, target string) bool {
-	if base == target {
-		return true
-	}
-	return strings.HasPrefix(target, strings.TrimRight(base, "/")+"/")
-}
-
 // --- Metrics handlers ---
 
 func (r *Router) metricsSystem(w http.ResponseWriter, req *http.Request) {