v0.11.0 — Phase C: Storage Init Wizard, Data Migration & Startup Fix

- Startup ping: fire heartbeat + health + hub report immediately on boot
  (5s delay after scheduler start, instead of waiting 5-15 min for first tick)

- Storage init wizard: new internal/storage/ package with disk scanning
  (lsblk -J), format+mount pipeline (sfdisk → mkfs.ext4 → blkid → fstab →
  mount → chown), safety guards (system disk detection, confirmation "FORMÁZÁS"),
  progress channel, auto-register in settings.json

- Data migration: MigrateAppData() with rsync --info=progress2 progress parsing,
  stop/rsync/update-config/start flow, rollback on failure, old data preserved

- New pages: /settings/storage/init (wizard), /stacks/{name}/migrate (migration)
- New API routes: /api/storage/{scan,init,init/status,migrate,migrate/status}
- Deploy page: storage info section for deployed apps (path, size, free, migrate link)
- Settings page: "Mozgatás" button per app in storage path details
- Container: privileged: true, /dev:/dev, /etc/fstab:/host-fstab, /run/udev:/run/udev:ro
- Dockerfile: add util-linux, e2fsprogs, rsync, parted for disk ops

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

controller/internal/storage/safety_linux.go

@@ -0,0 +1,102 @@
+//go:build linux
+
+package storage
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+	"syscall"
+	"time"
+)
+
+// IsSystemDisk checks if the given device path overlaps with the root filesystem device.
+// Returns true if the device is (or is the parent of) the system disk.
+func IsSystemDisk(devicePath string) (bool, error) {
+	// Get the block device major number of the root filesystem
+	var rootStat syscall.Stat_t
+	if err := syscall.Stat("/", &rootStat); err != nil {
+		return false, fmt.Errorf("cannot stat /: %w", err)
+	}
+
+	// Get block device info of the target device
+	var devStat syscall.Stat_t
+	if err := syscall.Stat(devicePath, &devStat); err != nil {
+		return false, fmt.Errorf("cannot stat %s: %w", devicePath, err)
+	}
+
+	// Compare major device numbers
+	rootMajor := rootStat.Dev >> 8 & 0xff
+	devMajor := devStat.Rdev >> 8 & 0xff
+	if rootMajor == devMajor {
+		return true, nil
+	}
+
+	return false, nil
+}
+
+// IsDeviceMounted checks if a device or any of its partitions is currently mounted.
+func IsDeviceMounted(devicePath string) (bool, error) {
+	data, err := os.ReadFile("/proc/mounts")
+	if err != nil {
+		return false, fmt.Errorf("cannot read /proc/mounts: %w", err)
+	}
+
+	base := filepath.Base(devicePath)
+	for _, line := range strings.Split(string(data), "\n") {
+		fields := strings.Fields(line)
+		if len(fields) < 2 {
+			continue
+		}
+		dev := fields[0]
+		devBase := filepath.Base(dev)
+		if devBase == base || strings.HasPrefix(devBase, base) {
+			return true, nil
+		}
+	}
+	return false, nil
+}
+
+// IsMountPathInUse checks if a path is already used as a mount point.
+func IsMountPathInUse(mountPath string) (bool, error) {
+	data, err := os.ReadFile("/proc/mounts")
+	if err != nil {
+		return false, fmt.Errorf("cannot read /proc/mounts: %w", err)
+	}
+	mountPath = filepath.Clean(mountPath)
+	for _, line := range strings.Split(string(data), "\n") {
+		fields := strings.Fields(line)
+		if len(fields) < 2 {
+			continue
+		}
+		if filepath.Clean(fields[1]) == mountPath {
+			return true, nil
+		}
+	}
+	return false, nil
+}
+
+// BackupFstab creates a dated backup of the fstab file.
+func BackupFstab(fstabPath string) error {
+	data, err := os.ReadFile(fstabPath)
+	if err != nil {
+		return fmt.Errorf("cannot read %s: %w", fstabPath, err)
+	}
+	backupPath := fstabPath + ".bak." + time.Now().Format("20060102")
+	return os.WriteFile(backupPath, data, 0644)
+}
+
+// AppendFstabEntry appends a UUID-based fstab entry.
+func AppendFstabEntry(fstabPath, uuid, mountPoint, fsType, options string) error {
+	entry := fmt.Sprintf("\nUUID=%s\t%s\t%s\t%s\t0 2\n", uuid, mountPoint, fsType, options)
+	f, err := os.OpenFile(fstabPath, os.O_APPEND|os.O_WRONLY, 0644)
+	if err != nil {
+		return fmt.Errorf("cannot open fstab for writing: %w", err)
+	}
+	defer f.Close()
+	if _, err := f.WriteString(entry); err != nil {
+		return fmt.Errorf("cannot write fstab entry: %w", err)
+	}
+	return nil
+}