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/duskpsp/CMakeLists.txt

@@ -21,5 +21,6 @@ add_subdirectory(log)
 if(DUSK_NETWORK)
   add_subdirectory(network)
 endif()
+add_subdirectory(save)
 add_subdirectory(system)
 add_subdirectory(time)

src/duskpsp/save/CMakeLists.txt

@@ -0,0 +1,9 @@
+# Copyright (c) 2026 Dominic Masters
+#
+# This software is released under the MIT License.
+# https://opensource.org/licenses/MIT
+
+target_sources(${DUSK_LIBRARY_TARGET_NAME}
+  PUBLIC
+    savedevicepsp.c
+)

src/duskpsp/save/savedeviceplatform.h

@@ -0,0 +1,16 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "savedevicepsp.h"
+
+#define SAVE_DEVICE_COUNT 1
+
+#define saveDevicePlatformInit saveDevicePSPInit
+#define saveDevicePlatformUpdate saveDevicePSPUpdate
+#define saveDeviceCheckAvailabilityPlatform saveDevicePSPCheckAvailability
+#define saveDevicePlatformDispose saveDevicePSPDispose

src/duskpsp/save/savedevicepsp.c

@@ -0,0 +1,52 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "save/savedevice.h"
+#include "save/savedevicepsp.h"
+#include "assert/assert.h"
+#include <pspiofilemgr.h>
+
+errorret_t saveDevicePSPInit(savedevice_t *device) {
+  assertNotNull(device, "device cannot be null");
+
+  device->state = SAVE_DEVICE_STATE_UNKNOWN;
+
+  errorOk();
+}
+
+errorret_t saveDevicePSPUpdate(savedevice_t *device) {
+  assertNotNull(device, "device cannot be null");
+  assertIsMainThread("Invalid thread");
+  errorOk();
+}
+
+void saveDevicePSPCheckAvailability(savedevice_t *device) {
+  assertNotNull(device, "device cannot be null");
+  assertIsMainThread("Invalid thread");
+  assertTrue(
+    device->state == SAVE_DEVICE_STATE_CHECKING_AVAILABILITY,
+    "Device state incorrect?"
+  );
+
+  // Confirm the memory stick is actually reachable - the real save/load
+  // (via sceUtilitySavedata) only reports failure once a save/load is
+  // attempted, so this is checked separately up front.
+  SceIoStat stat;
+  if(sceIoGetstat(SAVE_DEVICE_PSP_ROOT, &stat) < 0) {
+    device->state = SAVE_DEVICE_STATE_UNAVAILABLE;
+    device->reasonKey = "save.psp.no_memory_stick";
+    return saveDeviceFireCallback(device);
+  }
+
+  device->state = SAVE_DEVICE_STATE_AVAILABLE;
+  device->reasonKey = NULL;
+  saveDeviceFireCallback(device);
+}
+
+errorret_t saveDevicePSPDispose(savedevice_t *device) {
+  errorOk();
+}

src/duskpsp/save/savedevicepsp.h

@@ -0,0 +1,52 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "error/error.h"
+
+// PSP only ever exposes one save device - the memory stick.
+#ifndef SAVE_DEVICE_PSP_ROOT
+  #define SAVE_DEVICE_PSP_ROOT "ms0:/"
+#endif
+
+typedef struct {
+  void *nothing;
+} savedeviceplatform_t;
+
+typedef struct savedevice_s savedevice_t;
+
+/**
+ * Initializes the save device platform.
+ *
+ * @param device The save device platform to initialize.
+ * @return Error state if any.
+ */
+errorret_t saveDevicePSPInit(savedevice_t *device);
+
+/**
+ * Updates the save device platform.
+ *
+ * @param device The save device platform to update.
+ * @return Error state if any.
+ */
+errorret_t saveDevicePSPUpdate(savedevice_t *device);
+
+/**
+ * Requests the device to check its availability, this will call the callback
+ * whence completed.
+ *
+ * @param device The save device platform to check availability.
+ */
+void saveDevicePSPCheckAvailability(savedevice_t *device);
+
+/**
+ * Disposes of the save device platform.
+ *
+ * @param device The save device platform to dispose.
+ * @return Error state if any.
+ */
+errorret_t saveDevicePSPDispose(savedevice_t *device);