pub fn migrate_data_directory(
legacy: &Path,
destination: &Path,
) -> Result<(), DataMigrationError>Expand description
Prepares destination from legacy application data, retaining the original directory.
An existing destination wins without merging. Copies are verified privately and published
atomically; an interrupted copy is never treated as an established destination.
Call this only for production paths, before opening a runtime. Explicit overrides, tests,
development builds and previews must continue using their own directories directly.
ยงErrors
Returns an actionable error for live writers, unavailable paths, unsupported file types, corrupt databases, or failed copy/verification/publication. No existing destination is replaced.