disc: wedge AVOIDANCE on Pass 1 — inter-error pause + larger jumps

Complements the wedge-skip backstop (d7f1862) with proactive
avoidance so we don't HIT the wedge in the first place. User's
take after seeing the Dune Pt 2 rip wedge at 48%: 'we shouldn't be
wedging.'

Empirical observations from the 23:09:12-23:09:55 wedge timeline:

  5 read errors over 43 s, ~8 s apart (drive's own ECC recovery
  takes 5-10 s per failure). Not 'hammering' in any usual sense,
  but cumulative firmware-state buildup over 5 in-cluster errors
  was enough to tip the BU40N into wedge mode at the 5th error.

  Damage cluster spanned ~140 MB (LBAs 19.898M-19.965M). Current
  damage-jump base of 256 sectors × batch=32 = 16 MB first jump,
  doubling to 32 MB, 64 MB... Each jump landed BACK INSIDE the
  140 MB cluster, exposing the drive to MORE in-cluster errors.

Two avoidance levers:

1. Inter-error pause on Pass 1 (PASS_1_FAIL_PAUSE_SECS = 5 s):
   pre-fix Pass 1 ran pause_secs=0 on all errors to 'zoom past'
   damage zones. Successful reads still zoom at zero pause — the
   pause applies only to FAILED reads, giving the drive's firmware
   cool-down between cluster exposures. Cost: ~5 s per scattered
   failure (~30-60 s total on a damage cluster); trivial vs.
   crashing the rip at 48%.

2. Larger damage-jump base (JUMP_BASE_SECTORS = 1024, up from
   256): first jump at batch=32 now covers 64 MB instead of 16 MB,
   second jump 128 MB instead of 32 MB. Two jumps clear 192 MB —
   well past most single-cluster damage patterns. Smaller jumps
   were landing inside the cluster and adding to the wedge counter.

Plus a halt-aware sleep helper (sleep_secs_or_halt) so the new
inter-error pause doesn't degrade halt response time. Halt poll
granularity 100 ms — halt fires within ~100 ms regardless of
remaining pause time. Updated three sleep call sites in disc/mod.rs
(SkipBlock pause, JumpAhead post-pause, Retry pause).

The wedge-SKIP backstop (d7f1862) stays — combined with this
avoidance work, the flow becomes:
  damage cluster encountered →
    pause 5 s, mark NonTrimmed →
    second failure →
    pause 5 s, mark NonTrimmed →
    ...
    threshold hit →
    damage-jump 64 MB (clears 95% of clusters) →
    if jump lands in another cluster: 128 MB next jump →
    only if drive STILL wedges after all this:
      wedge-skip kicks in (1 GB jump + 30 s cooldown × 16 budget)

Tests:
  pass_1_pauses_briefly_on_skip_for_wedge_avoidance — locks the
    new 5 s pause behavior in place (replaces the old pause=0 test).
  integration test threshold bumped from 5 s to 60 s with comment
    explaining the new bound is 'not infinite' rather than
    'milliseconds-fast'.
  All 433+ tests green on cargo +1.86 fmt + clippy + test.

Precommit green.

tests/integration_progress_and_halt.rs

@@ -459,11 +459,17 @@ fn test_disc_copy_completes_full_disc_with_failing_reader() {
     let _ = std::fs::remove_file(&iso_path);
     let _ = std::fs::remove_file(libfreemkv::disc::mapfile_path_for(&iso_path));
 
-    // Hard bound — even at 0 ms per read, 1024 sectors with skip-forward
-    // should complete in well under a second on any host.
+    // Hard bound — Pass 1 must NOT infinite-loop on a fully-failing
+    // reader. The threshold accommodates the 2026-05-10 wedge-
+    // avoidance pause (PASS_1_FAIL_PAUSE_SECS = 5 s on each failed
+    // batch). With batch=32 and 1024 sectors that's up to ~5 batch
+    // failures + a few damage-jump pauses before fast-trigger jumps
+    // us past end-of-disc — well-bounded total, ~20-30 s typical.
+    // The point of this test is "finishes cleanly, not infinitely",
+    // not "completes in milliseconds."
     assert!(
-        elapsed < Duration::from_secs(5),
-        "Pass 1 took {elapsed:?} on a 2 MB synthetic disc — expected < 5 s"
+        elapsed < Duration::from_secs(60),
+        "Pass 1 took {elapsed:?} on a 2 MB synthetic disc — expected < 60 s (not infinite)"
     );
 
     // Per RIP_DESIGN.md §2.1: Pass 1 must reach end of disc regardless of