nx_doc_heal_let.nx

nx_doc_heal_let.nx -- DOCTOR auto-fixer (doc_heal family) for the #1 empty-.s cause: a `let` binding that is later REASSIGNED (let is immutable in NishiLang -> reassign silently compile-fails to an empty .s). dhl_heal rewrites each offending `let NAME` -> `var NAME`, and ONLY those: it does NOT touch a clean `let` (never reassigned), a `==` comparison, or a `NAME[i] = ...` index-assignment (the pointer isn't reassigned). This turns the team from autonomous RECALL (NX-LET-REASSIGN) into autonomous FIX. Pure string transform; the wired Doctor runs it on an empty-.s source then recompiles. license_tier: ORIGINAL