v0.10.0: Phase B — Storage Management UI Polish & Health Severity Fix

- Health severity fix: mount-point check downgraded from issue (FAIL) to warning (WARN)
- All storage health messages translated to Hungarian
- Success flash messages for all storage operations
- Edit storage path labels (inline edit UI + backend)
- App details per storage path on settings page (expandable list with names + sizes)
- Storage badge on stacks page showing which storage each app uses
- Deploy dropdown with free space display and low-space warning (<20%)
- Filesystem & disk info on settings page (ext4/btrfs, device, model via findmnt)
- Backup page storage context with per-app storage label badges

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

controller/internal/system/mounts_other.go

@@ -47,3 +47,13 @@ type DiskUsageInfo struct {
 
 // GetDiskUsage returns nil on non-Linux.
 func GetDiskUsage(_ string) *DiskUsageInfo { return nil }
+
+// FSInfo holds filesystem type, device, and disk model info.
+type FSInfo struct {
+	FSType string
+	Device string
+	Model  string
+}
+
+// GetFSInfo returns nil on non-Linux.
+func GetFSInfo(_ string) *FSInfo { return nil }