fix: contract macro inside struct body causes parse error

[noahgift]

Error

error: unexpected token: !
   |            ---------- while parsing this struct
54 |     contract_pre_patch_apply!(basis);
   |                             ^ unexpected token after this

contract_pre_patch_apply!() expands to debug_assert!() which is a statement, not a struct field. The macro call needs to be moved from the struct body to a function/method where it can execute as a runtime check.

Five-Whys

1. CI fails → compilation error in struct body
2. Macro call in struct → macros expand to statements, not fields
3. Likely copy-paste error placing contract assertion in wrong location