v0.5.9: fix OptiPlex heap crash — EBS retry must not rebuild the free list

Root cause: on real hardware SetMode can invalidate the pre-captured
ExitBootServices map key, so EBS fails and the retry refreshed the map
via capture_memory_map -> init_heap, which REBUILT the free list from
the raw map and wiped the allocation state of every pre-EBS live object
(the display shadow and the vt grids). Their spans became free while
still live, later allocations carved inside the shadow, and the display
writes clobbered them — zeroed back-pointers (family A ptr=0x404443e0
block=0x0) and gray glyph pixels (family B 0xaaaaaa00aaaaaa = 0x00AAAAAA
= PALETTE[7] fg-7 text colour, not a firmware scrub).

Fix: refresh_and_exit now re-captures the map and returns a fresh EBS
key without rebuilding the free list (refresh_map_key); the free list is
the authoritative live-allocation state. Verified in QEMU under a forced
EBS failure (SIMULATE_EBS_FAILURE test hook): verify ok, probe NOT free,
flhead outside the shadow — identical to a clean boot, and the full
shell sequence is crash-free.

Also: removed the crash-family debug markers from the screen (boot-time
heapdbg lines, vt verify marker, shadow marker) — the vt grid self-check
stays serial-only. Version 0.5.8 -> 0.5.9.

0 files changed, 0 insertions, 0 deletions