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/iwd/iwd_manager.h

@@ -0,0 +1,32 @@
+#ifndef IWD_MANAGER_H
+#define IWD_MANAGER_H
+
+#include <Eldbus.h>
+#include <Eina.h>
+
+typedef enum {
+   IWD_STATE_OFF,
+   IWD_STATE_IDLE,
+   IWD_STATE_SCANNING,
+   IWD_STATE_CONNECTING,
+   IWD_STATE_CONNECTED,
+   IWD_STATE_ERROR,
+} Iwd_State;
+
+typedef struct _Iwd_Manager Iwd_Manager;
+
+Iwd_Manager *iwd_manager_new (Eldbus_Connection *conn);
+void         iwd_manager_free(Iwd_Manager *m);
+
+Iwd_State    iwd_manager_state    (const Iwd_Manager *m);
+const Eina_List *iwd_manager_devices (const Iwd_Manager *m);
+
+void         iwd_manager_scan_request    (Iwd_Manager *m);
+void         iwd_manager_set_powered     (Iwd_Manager *m, Eina_Bool on);
+
+/* Event callback signature for UI layer */
+typedef void (*Iwd_Manager_Cb)(void *data, Iwd_Manager *m);
+void iwd_manager_listener_add (Iwd_Manager *m, Iwd_Manager_Cb cb, void *data);
+void iwd_manager_listener_del (Iwd_Manager *m, Iwd_Manager_Cb cb, void *data);
+
+#endif