LoadZIMPtr() writes width[]/height[]/image[] as arrays (one entry per
mip level, up to ZIM_MAX_MIP_LEVELS) whenever the file has
ZIM_HAS_MIPS set, per its documented contract - but this caller passed
plain scalar locals. A texture-replacement .zim file with that flag
set caused multiple out-of-bounds stack writes. Now passes properly
sized arrays and only uses level 0, matching the existing "we don't
support ZIM mips yet" behavior. Also fixes a pre-existing leak of
image[0] on the "changed since header read" error path.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01L4QAoxV2KY7ek4PcZw3WvY
