fix(agents-init): move argv assignments after guard in gitignore helper

functions/_agents_init_ensure_gitignore.fish

@@ -21,9 +21,6 @@
 # EXAMPLE
 #   _agents_init_ensure_gitignore /home/user/myproject "AGENTS/"
 function _agents_init_ensure_gitignore
-    set -l root    $argv[1]
-    set -l pattern $argv[2]
-
     set -l c_ok    (set_color green)
     set -l c_reset (set_color normal)
 
@@ -32,6 +29,9 @@ function _agents_init_ensure_gitignore
         return 1
     end
 
+    set -l root    $argv[1]
+    set -l pattern $argv[2]
+
     set -l gitignore "$root/.gitignore"
 
     # Prefer git check-ignore (respects wildcards, parent globs, negations).