• Free four leaked malloc'd buffers in codegen module/func-ref resolution (ns_name, mangled, rn, check_name/prefix)
• New util/xalloc.h (xmalloc/xcalloc/xrealloc) — abort-on-OOM helpers matching the inline pattern already in buf.c/arena.c
• Routed all unchecked malloc/calloc/realloc calls in codegen.c, typechecker.c, types.c, scope.c, error.c through the xalloc helpers
• Removed dead "skip on OOM" branches in typechecker that were silently producing incomplete state on allocation failure

Performance

• error_codes.c: chained strcmp lookup → sorted bsearch

• typechecker/types.c::type_from_name: ~25 chained strcmps → static sorted bsearch table dispatching singletons + sized variants in one shot

• codegen.c: replaced O(struct_count × field_count) scan in the member-call fallback heuristic with a lazily-built (field_name, struct_name) index over only func-typed fields

• codegen.c::find_func: linear scan → separate sorted view (funcs_by_name) + bsearch. cg->all_funcs keeps insertion order so emission and prefix-match scans

• stream arg in non-container char print (emitf had 2 %s and 3 args)

• heap-allocated mangled buffer in monomorphisation forward-decl loop instead of letting a stack address briefly live in the AST

• replaced two duplicated case-insensitive true/false parsers with strncasecmp
  -io.copy_file now creates the destination with mode 0644 via open()+fdopen() instead of fopen()'s 0666-mod-umask default
  — ez_arrays.remove_float needs bit-equal lookup; fmt_shortest_float is the canonical round-trip-precision idiom