v0.13.9: Disc::copy stall guard + SgIoTransport no-reopen-on-timeout

Fixes the silent Pass 1 hang observed on Dune 2 with v0.13.8 (drive
grinding through bad sectors at 0 KB/s, errs=0, no error surfaced).

Root cause: SgIoTransport::execute's reopen-after-poll-timeout opened
a fresh /dev/sg* fd on the main thread, which serialized against the
spawned close() of the old fd via the kernel's per-device state lock.
The userspace 1.5s timeout still fired, but the abandon-and-reopen
recovery itself blocked the main thread for as long as close() took.
Net: reads returned slowly, skip-forward fired on every iteration,
bytes_good never advanced.

- SgIoTransport::execute: on poll timeout, spawn close, set fd=-1,
  return Err. No reopen on the main thread. The transport is now
  invalidated until the consumer creates a fresh Drive.
- Disc::copy: add stall guard. CopyOptions.stall_secs (default 120s).
  If bytes_good doesn't advance for the threshold, break 'outer
  cleanly with complete=false, bytes_pending > 0 so Pass 2 retries
  pick up the NonTrimmed ranges with recovery=true 30s timeouts.
- New regression test: test_disc_copy_stall_detection_triggers_
  skip_forward in tests/integration_progress_and_halt.rs.

CHANGELOG.md

@@ -1,5 +1,43 @@
 # Changelog
 
+## 0.13.9 (2026-04-25)
+
+### Fix: Disc::copy silent stall + SgIoTransport reopen-after-timeout serialization
+
+Two correlated fixes for a hang observed live on the LG BU40N during a
+v0.13.8 rip of Dune: Part Two. At ~30 % progress through Pass 1
+(disc → ISO), `bytes_good` froze for 10+ minutes with `errs=0`,
+no error surfaced, drive not wedged.
+
+Root cause: `SgIoTransport::execute` (linux.rs) attempted to recover from
+a `poll()` timeout by spawning a background `close()` of the old fd and
+opening a fresh `/dev/sg*` fd on the main thread. On Linux, opening the
+SAME device while a prior fd is mid-close serializes via the kernel's
+per-device state lock — so the fresh `open()` blocks for as long as the
+close does (until the kernel completes the in-flight CDB). This undid
+the userspace 1.5 s timeout: each timed-out read added 60+ s to the
+next iteration. From `Disc::copy`'s perspective, reads kept returning
+Err slowly, the skip-forward path advanced `pos` but never `bytes_good`.
+
+Fixes:
+- `SgIoTransport::execute` no longer reopens on timeout. Spawns the
+  close, sets `self.fd = -1`, returns Err immediately. Subsequent
+  calls fail with `DeviceNotFound` (already gated at line 248).
+  Caller (Drive) is invalidated until reopened. Pass 2's
+  `Disc::patch` would need a fresh Drive; that's a v0.14 follow-up.
+- `Disc::copy` adds a stall guard. New `CopyOptions::stall_secs:
+  Option<u64>` (default 120 s). If `bytes_good` doesn't advance for
+  the threshold, breaks the outer loop with `complete: false,
+  bytes_pending > 0` so the caller's retry path picks up.
+
+Tests: new `test_disc_copy_stall_detection_triggers_skip_forward` in
+`tests/integration_progress_and_halt.rs` proves the guard fires within
+the configured threshold.
+
+Other:
+- Cosmetic: warning text "rip thread did not drain within 35s" updated
+  to 60s (matches the v0.13.8 timeout bump).
+
 ## 0.13.8 (2026-04-25)
 
 ### Version sync — no functional changes