Add PSP/GameCube/Wii save-device availability checks

PSP checks memory-stick reachability via sceIoGetstat. GameCube gets two
devices (CARD_SLOTA/CARD_SLOTB), each mounted via CARD_Init/CARD_Mount and
checked for free space via CARD_GetDirectory/CARD_GetBlockCount. Wii picks
between three storage methods at compile time (DUSK_SAVE_WII_METHOD =
NAND/CARD/SD in wii.cmake, default NAND via ISFS) since real hardware
behavior for the default is unverified.

Also fixes two pre-existing bugs found while build/runtime-testing this
across PPSSPP and Dolphin: wrong libogc language macros in
systemGetLocaleDolphin, and a missing SYS_STDIO_Report(true) call that
silently swallowed all guest console output in Dolphin.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/duskdolphin/save/savedeviceplatform.h

@@ -0,0 +1,44 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+
+// GameCube only ever has the CARD_SLOTA/CARD_SLOTB memory card devices.
+// Wii additionally picks between three storage methods, selected by
+// DUSK_SAVE_WII_METHOD in cmake/targets/wii.cmake:
+//  - NAND (default): real internal storage via ISFS, see
+//    savedevicedolphinnand.h for the caveats around this.
+//  - CARD: reuses the exact same GameCube memory card code, since libogc's
+//    CARD API transparently redirects to Wii's NAND-based GameCube memory
+//    card emulation.
+//  - SD: the SD card via libfat, same mechanism this project already uses
+//    for Dolphin/Wii asset loading (see assetdolphinfat.c).
+#if defined(DUSK_WII) && defined(DUSK_SAVE_WII_METHOD_NAND)
+  #include "savedevicedolphinnand.h"
+  #define SAVE_DEVICE_COUNT 1
+  #define saveDevicePlatformInit saveDeviceDolphinNandInit
+  #define saveDevicePlatformUpdate saveDeviceDolphinNandUpdate
+  #define saveDeviceCheckAvailabilityPlatform \
+    saveDeviceDolphinNandCheckAvailability
+  #define saveDevicePlatformDispose saveDeviceDolphinNandDispose
+#elif defined(DUSK_WII) && defined(DUSK_SAVE_WII_METHOD_SD)
+  #include "savedevicedolphinsd.h"
+  #define SAVE_DEVICE_COUNT 1
+  #define saveDevicePlatformInit saveDeviceDolphinSDInit
+  #define saveDevicePlatformUpdate saveDeviceDolphinSDUpdate
+  #define saveDeviceCheckAvailabilityPlatform \
+    saveDeviceDolphinSDCheckAvailability
+  #define saveDevicePlatformDispose saveDeviceDolphinSDDispose
+#else
+  #include "savedevicedolphincard.h"
+  #define SAVE_DEVICE_COUNT 2
+  #define saveDevicePlatformInit saveDeviceDolphinCardInit
+  #define saveDevicePlatformUpdate saveDeviceDolphinCardUpdate
+  #define saveDeviceCheckAvailabilityPlatform \
+    saveDeviceDolphinCardCheckAvailability
+  #define saveDevicePlatformDispose saveDeviceDolphinCardDispose
+#endif