b5b8ab092b
Whole C strings now cross as cstring (sx 1d17b0a): IN via to_cstring with literal coercion, OUT as ?cstring copied through sq_from_cstr (std from_cstring + substr) before sqlite's buffer dies. sq_cstr and the manual strlen loop are gone. column_text/column_blob/serialize deliberately stay ?*u8 + explicit byte counts — their payloads may carry interior NULs that a strlen would truncate. 21/21 green.