Update audio pipeline with extensive logging and defualt with fallbacks

src/audio/audio_manager.cpp

@@ -32,6 +32,7 @@ namespace radiantwave::audio
         if (lower.find("analog") != std::string::npos ||
             lower.find("built-in") != std::string::npos ||
             lower.find("builtin") != std::string::npos ||
+            lower.find("virtual") != std::string::npos ||
             lower.find("realtek") != std::string::npos ||
             lower.find("hda") != std::string::npos ||
             lower.find("speaker") != std::string::npos ||
@@ -85,6 +86,34 @@ namespace radiantwave::audio
             return false;
         }
 
+        // Startup diagnostics: which audio backend SDL picked (PipeWire, ALSA,
+        // Pulse, dummy, ...) and what playback devices it actually sees. This is
+        // the first place a "only the built-in speakers show up" report points;
+        // a single device here means SDL itself never enumerated the HDMI sink.
+        const char *driver = SDL_GetCurrentAudioDriver();
+        std::string driverName = driver ? driver : "(none)";
+        int deviceCount = 0;
+        SDL_AudioDeviceID *devices = SDL_GetAudioPlaybackDevices(&deviceCount);
+        std::string deviceNames;
+        if (devices)
+        {
+            for (int i = 0; i < deviceCount; ++i)
+            {
+                if (i)
+                {
+                    deviceNames += ", ";
+                }
+                const char *n = SDL_GetAudioDeviceName(devices[i]);
+                deviceNames += n ? n : "(unnamed)";
+            }
+            SDL_free(devices);
+        }
+        logger::Logger::instance().info(
+            "Audio",
+            "SDL audio driver: " + driverName + "; " +
+                std::to_string(deviceCount) + " playback device(s) [" +
+                (deviceNames.empty() ? "(none)" : deviceNames) + "]");
+
         // Try to open the mixer on the device previously persisted in config;
         // fall back to the system default when the configured device is gone.
         SDL_AudioDeviceID targetId = SDL_AUDIO_DEVICE_DEFAULT_PLAYBACK;
@@ -247,7 +276,21 @@ namespace radiantwave::audio
         }
         else
         {
-            list.push_back({"", "Built-In Speakers", 0});
+            if (devices)
+            {
+                SDL_free(devices);
+            }
+            const char *driver = SDL_GetCurrentAudioDriver();
+            // Zero enumerated devices is a symptom, not a real output. Surface
+            // the truth (a single "System Default" entry that still routes to
+            // whatever the OS default is) instead of pretending a fabricated
+            // device, and say which backend was active so kiosk logs show why.
+            logger::Logger::instance().debug(
+                "Audio",
+                "No playback devices enumerated (audio driver: " +
+                    std::string(driver ? driver : "none") +
+                    "); falling back to the system default");
+            list.push_back({"", "System Default", 0});
         }
 
         return list;

src/audio_settings_page.cpp

@@ -531,7 +531,7 @@ void AudioSettingsPage::render(SDL_Renderer* renderer) {
     }
 
     std::string devName = (currentDeviceIndex_ >= 0 && currentDeviceIndex_ < static_cast<int>(devices_.size()))
-        ? devices_[currentDeviceIndex_].friendly_name : "Built-In Speakers";
+        ? devices_[currentDeviceIndex_].friendly_name : "System Default";
     deviceText_.ensure(renderer, fontHeader_, "Device: " + devName, white);
     if (deviceText_.texture) {
         SDL_FRect dst{500.0f, currentY, deviceText_.width, deviceText_.height};

tests/test_audio.cpp

@@ -8,6 +8,7 @@ TEST(AudioTest, FriendlyDeviceNameMapping) {
     EXPECT_EQ(mapToFriendlyDeviceName("AMD Radeon HD Audio Controller HDMI"), "TV / HDMI Monitor");
     EXPECT_EQ(mapToFriendlyDeviceName("USB Audio Headset Dongle"), "USB Audio Device");
     EXPECT_EQ(mapToFriendlyDeviceName("bluez_sink.00_11_22_33_44_55"), "Bluetooth Audio");
+    EXPECT_EQ(mapToFriendlyDeviceName("Virtual Speaker"), "Built-In Speakers");
     EXPECT_EQ(mapToFriendlyDeviceName(""), "Default Audio Output");
 }
 
@@ -30,6 +31,7 @@ TEST(AudioTest, GetPlaybackDevicesFallsBackWithIdZeroWhenNone) {
     for (const auto& d : devices) {
         if (d.raw_name.empty()) {
             EXPECT_EQ(d.id, 0u);
+            EXPECT_EQ(d.friendly_name, "System Default");
         }
     }
 }