LocalHeap::parse_in reads the header in one bounded read,
validate_free_list_in reads each free block's two lengths, and
read_string_in reads from the string to the end of the data segment
once and looks for the terminator there. The &[u8] methods are wrappers.
New test: a heap without free space, with a valid free block and with a
free block overrunning the segment, cut at every length, parse, validate
and read strings identically through a read_at-only CountingStorage.
Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>