libfreemkv: dir:// — decrypted file-tree extraction (Disc::extract_tree)

Sibling of Disc::copy specialized to write per-file instead of a whole ISO
image, decrypting on the way out: walk the UDF tree, read each file's extents
through the shared DecryptingSectorSource (AACS unit-aligned, CSS per-VTS),
strip AACS/, sanitize host paths per component, .partial+rename, 1-shot with
per-file loss accounting (no mapfile; recovery stays the iso:// multipass
path). Reuses UdfFs + the decrypt seam; only the per-file orchestration is new.

src/disc/mod.rs

@@ -12,6 +12,7 @@ mod bluray;
 mod dvd;
 pub mod dvd_audio_probe;
 mod encrypt;
+mod extract;
 pub mod mapfile;
 mod patch;
 pub mod read_error;
@@ -28,6 +29,7 @@ use encrypt::HandshakeResult;
 // so the public surface keeps the structured metadata together. Callers map
 // these to display text in their own locale.
 pub use crate::labels::{LabelPurpose, LabelQualifier};
+pub use extract::{ExtractOptions, ExtractResult, FileResult};
 
 // ─── Public types ───────────────────────────────────────────────────────────