Phase 0: scaffold e_iwd Enlightenment module

Meson build, module entry points, and stub layout for the iwd backend
(D-Bus client, gadget, popup, config, UI widgets). Bodies are TODOs;
this compiles against EFL/E headers but performs no D-Bus work yet.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/e_mod_popup.c

@@ -0,0 +1,11 @@
+#include "e_mod_main.h"
+#include "e_mod_popup.h"
+#include "ui/wifi_list.h"
+#include "ui/wifi_status.h"
+
+/* TODO: build the popup window with current connection panel,
+ *       network list, and action buttons. */
+
+void e_iwd_popup_toggle(Evas_Object *anchor EINA_UNUSED) { }
+void e_iwd_popup_close(void) { }
+void e_iwd_popup_refresh(void) { }