Nyx: emuMMC Manage window, Tools UI, and misc updates

- Add gui_emu_tools: emuMMC Manage window with correct positioning (LV_PROTECT_PARENT + re-parent to win)
- Tools: single SD button (tap = SD partition manager, 3s hold = eMMC)
- Remove emuSD from Nyx UI (tabs, UMS, partition manager); keep bootloader emusd
- Shorten Create emuMMC description text by one character
- Storage/build/config and dependency updates

Co-authored-by: Cursor <cursoragent@cursor.com>

nyx/nyx_gui/storage/sfd.h

@@ -0,0 +1,16 @@
+#ifndef _SFD_H
+#define _SFD_H
+
+#include <storage/sdmmc.h>
+#include <utils/types.h>
+
+int sfd_read(u32 sector, u32 count, void *buff);
+int sfd_write(u32 sector, u32 count, void *buff);
+
+bool sfd_file_based_init(const char *base_path);
+bool sfd_init(sdmmc_storage_t *storage, u32 offset, u32 size);
+void sfd_end();
+
+sdmmc_storage_t *sfd_get_storage();
+
+#endif