Function prepare_content_restore 

pub fn prepare_content_restore(
    doc: &AutoCommit,
    schema: &'static HistoryRestoreSchema,
    current_heads: &[ChangeHash],
    target_heads: &[ChangeHash],
) -> Result<PreparedContentRestore, RestoreError>

Prepare exact content restoration without mutating or committing the input.

Both current and historical content must satisfy the registered schema. Targets with content conflicts or rich-text blocks are unsupported, as is any record whose history created a Table object. All replayed sequence marks use ExpandMark::None for their current ranges. Whole Map values at map-addressed properties retain their current object identities when the current and target kinds match, recursively for map-addressed descendants. Other changed whole values may be recreated. Mixed structural ancestors and retained entities keep current identities. This value grants no authority: the host must check the reviewed resource, lifetime and current permission inside its exclusive record action frame.

Errors

Returns a typed error for pending edits, stale heads, invalid registration, unavailable target history, unsupported content, or failed validation.