[client] clipboard: add transport provider interface

Route clipboard exchange through a provider interface. Connected
transports take priority while SPICE remains the fallback.

Track asynchronous X11 and Wayland transfers by request, preserving
clipboard ownership across provider changes.

Use PureSpice clipboard status notifications for capability and
lifecycle updates.

client/src/clipboard.h

@@ -18,13 +18,26 @@
  * Temple Place, Suite 330, Boston, MA 02111-1307 USA
  */
 
-#include <purespice.h>
-#include "interface/displayserver.h"
+#ifndef _H_LG_CLIENT_CLIPBOARD_
+#define _H_LG_CLIENT_CLIPBOARD_
 
-LG_ClipboardData cb_spiceTypeToLGType(const PSDataType type);
-PSDataType cb_lgTypeToSpiceType(const LG_ClipboardData type);
+#include "interface/clipboard.h"
 
-void cb_spiceNotice(const PSDataType type);
-void cb_spiceData(const PSDataType type, uint8_t * buffer, uint32_t size);
-void cb_spiceRelease(void);
-void cb_spiceRequest(const PSDataType type);
+void lgClipboard_init(void);
+void lgClipboard_free(void);
+void lgClipboard_setLocalAvailable(bool available);
+
+void lgClipboard_setFallback(const LG_ClipboardOps * ops, void * opaque);
+void lgClipboard_setTransport(const LG_ClipboardOps * ops, void * opaque);
+void lgClipboard_dropTransport(void);
+
+void lgClipboard_release(void);
+void lgClipboard_notifyTypes(
+    const LG_ClipboardData types[], size_t count);
+void lgClipboard_data(LG_ClipboardRequest request,
+    LG_ClipboardData type, const void * data, size_t size);
+void lgClipboard_abort(LG_ClipboardRequest request);
+bool lgClipboard_request(LG_ClipboardData type,
+    LG_ClipboardReplyFn replyFn, void * opaque);
+
+#endif