cfg: asio driver selector must list both 32-bit and 64-bit drivers (#734)

## Link to GitHub Issue or related Pull Request, if one exists
#730 

## Description of change
spicecfg is a 32-bit application. When it uses the ASIO SDK it only saw
the 32-bit drivers.

There are some ASIO drivers that have different names under 32-bit and
64-bit (Xonar AE is one of them)... so we have to manually scan the
registry and surface both the WOW32 and WOW64 nodes.

## Testing
<img width="329" height="309" alt="image"
src="https://github.com/user-attachments/assets/7abecf76-6835-4df5-8c2e-e7b425130f4c"
/>

Checked both 32-bit and 64-bit configurator, identical results.

src/spice2x/hooks/audio/asio_driver_scan.cpp

@@ -0,0 +1,74 @@
+#include "asio_driver_scan.h"
+
+#include <algorithm>
+
+#include <windows.h>
+
+#include "util/utils.h"
+
+namespace hooks::audio {
+
+    static constexpr char ASIO_REG_PATH[] = "software\\asio";
+    static constexpr char ASIO_REG_DESC[] = "description";
+
+    // enumerate a single registry view, appending to entries while merging
+    // duplicates discovered in another view. Drivers are matched by name (not
+    // CLSID): the game's ASIO loader selects drivers by name, and some vendors
+    // register the same CLSID under different 32-bit/64-bit names (e.g. "XONAR
+    // SOUND CARD" vs "XONAR SOUND CARD(64)"), which are distinct user choices.
+    static void scan_view(
+            REGSAM wow64_flag,
+            bool is_64bit,
+            std::vector<AsioDriverScanEntry> &entries) {
+
+        HKEY hkEnum = nullptr;
+        if (RegOpenKeyExA(HKEY_LOCAL_MACHINE, ASIO_REG_PATH, 0,
+                KEY_READ | wow64_flag, &hkEnum) != ERROR_SUCCESS) {
+            return;
+        }
+
+        char key_name[256];
+        for (DWORD index = 0;
+             RegEnumKeyA(hkEnum, index, key_name, sizeof(key_name)) == ERROR_SUCCESS;
+             index++) {
+
+            // read description (display name), fall back to the key name
+            char desc[256] = { 0 };
+            DWORD size = sizeof(desc);
+            std::string name = key_name;
+            if (RegGetValueA(hkEnum,
+                             key_name,
+                             ASIO_REG_DESC,
+                             RRF_RT_REG_SZ | wow64_flag,
+                             nullptr,
+                             desc,
+                             &size) == ERROR_SUCCESS && desc[0]) {
+                name = desc;
+            }
+
+            // merge with an existing entry from the other view (match by name)
+            const std::string name_lower = strtolower(name);
+            auto it = std::find_if(entries.begin(), entries.end(), [&](const auto &e) {
+                return strtolower(e.name) == name_lower;
+            });
+            if (it == entries.end()) {
+                entries.push_back({ name });
+                it = entries.end() - 1;
+            }
+            it->found_32bit |= !is_64bit;
+            it->found_64bit |= is_64bit;
+        }
+
+        RegCloseKey(hkEnum);
+    }
+
+    std::vector<AsioDriverScanEntry> scan_asio_drivers() {
+        std::vector<AsioDriverScanEntry> entries;
+
+        // 64-bit view first so it wins ordering when present in both
+        scan_view(KEY_WOW64_64KEY, true, entries);
+        scan_view(KEY_WOW64_32KEY, false, entries);
+
+        return entries;
+    }
+}

src/spice2x/hooks/audio/asio_driver_scan.h

@@ -0,0 +1,15 @@
+#pragma once
+
+#include <string>
+#include <vector>
+
+namespace hooks::audio {
+
+    struct AsioDriverScanEntry {
+        std::string name;
+        bool found_32bit = false;
+        bool found_64bit = false;
+    };
+
+    std::vector<AsioDriverScanEntry> scan_asio_drivers();
+}