verify: container-kind seam (HD-DVD-ready) + skip units with unread sectors

ContainerKind {Ts,Ps} + ClipLayout.container thread the post-decrypt structural check per clip; decryptability() dispatches it (TS: unit_is_clean_ts, PS: unit_is_clean_ps). New decrypt_unit_checked(unit,key,accept) decouples the container-agnostic AACS crypto from the format-specific acceptance (decrypt_unit delegates with the TS check). unit_is_clean_ps is the MPEG-2 PS pack-start check, documented UNVALIDATED for HD-DVD (.evo unit/seed/pack alignment must be confirmed on real media). clip_layouts assigns Ts today; .evo->Ps is the one-line HD-DVD hook.

reverify_iso now takes an is_finished predicate and SKIPS any unit with a non-Finished backing sector: we can't verify what wasn't read (a non-Finished sector is zero-filled because the drive read failed there), and must never waste a key lookup on a block the read already knows is bad. observe() (sweep) was already safe (only fed Good bytes).

src/disc/extract.rs

@@ -347,6 +347,10 @@ pub(crate) fn clip_layouts(reader: &mut dyn SectorSource) -> Vec<crate::disc::ve
             .map(|pf| crate::disc::verify::ClipLayout {
                 size: pf.size,
                 extents: pf.extents,
+                // Every AACS clip we enumerate today is BD-TS (`.m2ts`/`.ssif`).
+                // HD-DVD `.evo` (program stream) maps to `ContainerKind::Ps` here
+                // once `is_aacs_clip` recognises it — the one-line HD-DVD hook.
+                container: crate::disc::verify::ContainerKind::Ts,
             })
             .collect())
     })();