Hojun-Cho
90479fed68
An empty `[]` carries no element type; ww gets it only from a let annotation (the #45 retype). Both stages used to silently default the element to u8, and in value-form positions (return / call-arg) the lowering miscompiled — malloc(8) ignoring n, a 16B *u8|nomem where a 24B slice was expected (#5). Now every empty alloc that isn't a let-annotated binding fails to infer with a loud error, aligning ww DOWN to harec (ref/harec/src/check.c:1801-1802). Mechanism: clet / checkletassign flags the single alloc call node that a `let x: []T =` rescues (save/restore around the init walk); the alloc branch errors on any empty alloc that isn't that node. The #45 wide-T retype path is kept. wwstage needs an extra not-yet-stamped guard because resolvewalk re-types value nodes context-free after checkletassign. Tests: negative cstage-driver 729 (table-driven: bare-let, return, call-arg, assignment) + positive @test in attest_pass.ww exercising the u8 and the wide-i32 (#45) paths at runtime. Both stages reject symmetrically; byte-id verified on []u8 and []i32.