migrate

type Options struct {
	WorkDir     string
	DryRun      bool
	FromVersion int // -1 = auto-detect
}

type RepairReport struct {
	Kind   string // "orphan_snapshot", "missing_column", "invalid_config_key"
	Detail string
	Fixed  bool
}

type Report struct {
	FromVersion    int
	ToVersion      int
	DryRun         bool
	Steps          []StepReport
	Warnings       []string
	RowsMigrated   int
	FilesConverted int
}

type StepReport struct {
	From    int
	To      int
	Applied bool   // false when already up-to-date
	Note    string // human-readable summary
}