Replace read_with_binary_search + 3×5s light recovery with an adaptive
sizer that shrinks on failure (halve, 3-aligned ≥6) and probes back up
after 100 MiB (51,200 sectors) of clean reads. Descent cost is paid
once per bad region, not once per bad sector.
Emit BatchSizeChanged { new_size, reason } on shrink and probe-up.
Remove BinarySearch event — no longer produced.
Side fix: scsi/macos.rs one-liner for manual_c_str_literals clippy
lint that surfaced on a newer toolchain.
