dat: implement C deserialization codegen, improve coverage

[ribbanya]

A C library, tools/dat-cli/native, that reads the archives into the game's own types on any platform, from a schema melee-dat native codegen writes from the DWARF. It's a port of the walk that converts as it goes, so melee-dat native expect and the library's trace must agree: they do for all 7048 archives on 64-bit and 32-bit little-endian and 32-bit big-endian (under qemu), and every converted object reads back against its data. The dat preset builds it with the host's compiler and runs its tests in ctest.

• the schema is a directory of C, generated when configuring: a dat_type_* descriptor for each type, with its members, in a file for the header that declares it (types/<header>.c); roots by module (roots/Pl.c); type indices as an enum (DAT_TYPE_*)
• descriptors are designated initializers that refer to types by name, with expressions next to their members and annotations as written in comments (dat/schema.h)
• the walk lays queued objects out as they were reached, so typedef tags apply (the CPU attack lists' DAT_TERMINATED was ignored)
• CPU attack tables typed (ftCo_AttackList); stage param types moved into their headers; stage param fields typed as their data
• 47 dat_symbols.txt aliases that read stage data as material animations removed
• generated C casts only between different types; untyped data typed from the fields that point to it
• samples report --incomplete, why units aren't complete
• a native dev shell with the DWARF/dat tools, qemu and a ppc32 cross compiler; the default shell is what CI needs
• clang-tidy's checks stay on src/: tools/ and the generated schema opt out

🤖 Generated with Claude Code