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/patch.rs

@@ -1629,6 +1629,7 @@ impl Disc {
             bytes_good_total: s.bytes_good,
             bytes_unreadable_total: s.bytes_unreadable,
             bytes_pending_total: s.bytes_pending,
+            bytes_retryable_total: s.bytes_retryable,
             bytes_total_disc: total_bytes,
             disc_duration_secs: main_title.map(|t| t.duration_secs),
             bytes_bad_in_main_title: main_title_bad,