fix: isolate continuous-mode mic capture and clarify voice settings

- Use a separate Microphone instance for continuous-mode VAD monitoring
  so it no longer races with the transmit capture path.
- Respect selected input device in continuous-mode monitor subscription.
- Make talk-mode and Sonora processing labels clearer in settings UI.

src/iced-app/src/main.rs

@@ -991,15 +991,21 @@ impl App {
 
             // Continuous talk: monitor mic input when in continuous mode
             if self.talk_mode == audio::TalkMode::Continuous {
-                let mic = self.mic.clone();
+                let selected_input_device = self.selected_input_device.clone();
                 let session_id = self.session_id;
                 subs.push(Subscription::run_with_id(
-                    (session_id, "continuous"),
+                    (session_id, "continuous", selected_input_device.clone()),
                     iced::stream::channel(100, move |mut sender| async move {
+                        let mic = Arc::new(Mutex::new(audio::Microphone::new()));
                         let (sample_tx, sample_rx) = std::sync::mpsc::channel();
                         {
                             let mut mic_guard = mic.lock().await;
-                            if mic_guard.start(None, sample_tx).is_err() {
+                            let device = if selected_input_device.is_empty() {
+                                None
+                            } else {
+                                Some(selected_input_device.as_str())
+                            };
+                            if mic_guard.start(device, sample_tx).is_err() {
                                 return;
                             }
                         }

src/iced-app/src/view.rs

@@ -643,36 +643,59 @@ impl App {
                 .width(560),
         );
 
-        let talk_mode_text = match self.talk_mode {
-            audio::TalkMode::PushToTalk => "Push-to-Talk (hold V)",
-            audio::TalkMode::Continuous => "Continuous (voice activation)",
-        };
-
         let nc_label = self.nc_method.label();
         let sonora_noise_label = self.sonora_settings.noise_suppression_level.label();
 
         let voice_col = column![
-            text("Voice Activation Mode").size(13),
+            text("Talk Mode").size(13),
-            text(talk_mode_text).size(12).style(text::secondary),
+            text("Choose how your microphone starts transmitting.").size(12).style(text::secondary),
             vertical_space().height(8),
             text("Push-to-Talk Key").size(13),
             text("V (hold to talk)").size(12).style(text::secondary),
             vertical_space().height(8),
-            text("Noise Cancellation").size(13),
+            text("Microphone Processing Backend").size(13),
             text(nc_label).size(12).style(text::secondary),
         ]
         .spacing(4)
         .padding(16);
 
-        let voice_col = voice_col.push(
+        let voice_col = voice_col.push(row![
-            button(text("Toggle Voice Mode").size(11))
+            button(text("Push-to-Talk").size(11))
                 .padding([4, 12])
-                .style(theme::secondary_button)
+                .style(if self.talk_mode == audio::TalkMode::PushToTalk {
-                .on_press(Message::ToggleTalkMode),
+                    theme::primary_button
+                } else {
+                    theme::secondary_button
+                })
+                .on_press(if self.talk_mode == audio::TalkMode::PushToTalk {
+                    Message::Noop
+                } else {
+                    Message::ToggleTalkMode
+                }),
+            button(text("Voice Activation").size(11))
+                .padding([4, 12])
+                .style(if self.talk_mode == audio::TalkMode::Continuous {
+                    theme::primary_button
+                } else {
+                    theme::secondary_button
+                })
+                .on_press(if self.talk_mode == audio::TalkMode::Continuous {
+                    Message::Noop
+                } else {
+                    Message::ToggleTalkMode
+                }),
+        ]
+        .spacing(8)
+        .align_y(iced::Alignment::Center));
+
+        let voice_col = voice_col.push(
+            text("Advanced options below only affect microphone cleanup, not playback.")
+                .size(11)
+                .style(text::secondary),
         );
 
         let voice_col = noise_cancel::NoiseCancelMethod::all().iter().copied().fold(
-            voice_col.push(text("Noise Cancel Backend").size(11).style(text::secondary)),
+            voice_col.push(text("Processing backend").size(11).style(text::secondary)),
             |column, method| {
                 let label = method.label().to_string();
                 column.push(
@@ -691,7 +714,10 @@ impl App {
         let voice_col = if self.nc_method == noise_cancel::NoiseCancelMethod::Sonora {
             let voice_col = voice_col
                 .push(vertical_space().height(8))
-                .push(text("Sonora Noise Suppression").size(11).style(text::secondary))
+                .push(text("Advanced Sonora Processing").size(13))
+                .push(text("Tune noise cleanup, auto gain, and low-frequency filtering.").size(11).style(text::secondary))
+                .push(vertical_space().height(4))
+                .push(text("Noise Suppression Strength").size(11).style(text::secondary))
                 .push(text(sonora_noise_label).size(12).style(text::secondary));
 
             let voice_col = noise_cancel::NoiseSuppressionLevelSetting::all()
@@ -712,11 +738,12 @@ impl App {
 
             voice_col
                 .push(vertical_space().height(8))
+                .push(text("Automatic Gain Control").size(11).style(text::secondary))
                 .push(
                     button(text(if self.sonora_settings.agc_enabled {
-                        "AGC2: On"
+                        "AGC2 On"
                     } else {
-                        "AGC2: Off"
+                        "AGC2 Off"
                     })
                     .size(11))
                     .padding([4, 12])
@@ -727,11 +754,12 @@ impl App {
                     })
                     .on_press(Message::ToggleSonoraAgc),
                 )
+                .push(text("High-Pass Filter").size(11).style(text::secondary))
                 .push(
                     button(text(if self.sonora_settings.high_pass_enabled {
-                        "High-Pass: On"
+                        "High-Pass On"
                     } else {
-                        "High-Pass: Off"
+                        "High-Pass Off"
                     })
                     .size(11))
                     .padding([4, 12])