progress: expose bytes_retryable so 'lost' counts only failed reads

Add PassProgress::bytes_retryable_total (NonTrimmed/NonScraped — failed
and awaiting retry), distinct from bytes_pending_total which also folds
in not-yet-attempted (NonTried) bytes. Set it at every construction site
(Sweep from the snapshot, Patch from stats, 0 for sequential/placeholder
paths). The disc-level 'lost' display in the CLI can now use
unreadable+retryable instead of unreadable+pending, so a healthy
in-progress rip no longer reports its unread remainder as lost.

src/disc/extract.rs

@@ -613,6 +613,7 @@ fn report(opts: &ExtractOptions, done: u64, total: u64) -> bool {
                 bytes_good_total: done,
                 bytes_unreadable_total: 0,
                 bytes_pending_total: 0,
+                bytes_retryable_total: 0,
                 bytes_total_disc: total,
                 disc_duration_secs: None,
                 bytes_bad_in_main_title: 0,