Out-of-bounds Write via NAND Metadata Parsing at Mount in LevelX

Mounting an attacker-controlled NAND flash image (`lx_nand_flash_open()`) triggers an unbounded out-of-bounds heap **write** in LevelX's NAND flash-translation-layer metadata parser that overwrites a driver function pointer in the control block, giving a demonstrated control-flow hijack — RIP set to a full 8-byte attacker-chosen value (register-verified). Two accompanying OOB reads. All reproduced verbatim under ASan at HEAD `9f1cfdc`.