fix: add enable/disable methods to debug stub

The debug stub was missing the `enable()` and `disable()` methods that
the debug package provides. This caused errors when socket-cli re-bundles
the lib code and calls `debug.enable(namespace)`.

Author: jdalton

scripts/build-externals/stubs/debug.cjs

@@ -15,10 +15,16 @@ function debug() {
   return function noop() {}
 }
 
-// Common debug properties
+// Static properties matching the debug package API.
 debug.enabled = false
 debug.names = []
 debug.skips = []
 debug.formatters = {}
 
+// Enable/disable debug namespaces (no-op since debug is stubbed out).
+debug.enable = function enable() {}
+debug.disable = function disable() {
+  return ''
+}
+
 module.exports = debug