fix: resolve UI rework regressions in Dante/Analog/Network modes

- Remove undefined saved_r1_config/saved_r2_config variables in Dante mode TX power fields
- Fix quality_options used before assignment in USB/Network mode
- Fix Radio 2 input device reading from primary instead of secondary settings while streaming

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/auracast/server/multicast_frontend.py

@@ -835,7 +835,7 @@ else:
                     else:
                         input_device2 = None
                 else:
-                    input_device2 = saved_settings.get('input_device')
+                    input_device2 = saved_settings.get('secondary', {}).get('input_device')
                     st.selectbox(
                         "Input Device (Radio 2)",
                         [input_device2 or "No device selected"],
@@ -1095,7 +1095,7 @@ else:
             r1_tx_power = _tx_power_selectbox(
                 "TX Power (R1)",
                 key="dante_tx_power_r1",
-                default=saved_r1_config.get('advertising_tx_power', saved_settings.get('advertising_tx_power', TX_POWER_DEFAULT)),
+                default=saved_settings.get('advertising_tx_power', TX_POWER_DEFAULT),
                 disabled=is_streaming,
             )
 
@@ -1428,7 +1428,7 @@ else:
                 r2_tx_power = _tx_power_selectbox(
                     "TX Power (R2)",
                     key="dante_tx_power_r2",
-                    default=saved_r2_config.get('advertising_tx_power', saved_settings.get('secondary', {}).get('advertising_tx_power', TX_POWER_DEFAULT)),
+                    default=saved_settings.get('secondary', {}).get('advertising_tx_power', TX_POWER_DEFAULT),
                     disabled=is_streaming,
                 )
 
@@ -1612,6 +1612,7 @@ else:
     if audio_mode in ("USB", "Network"):
         # USB/Network: single set of controls shared with the single channel
         # Use saved settings if audio_mode matches, otherwise use defaults
+        quality_options = list(QUALITY_MAP.keys())
         saved_audio_mode = saved_settings.get('audio_mode')
         if saved_audio_mode in ("USB", "Network"):
             # Map saved sampling rate to quality label
@@ -1631,8 +1632,6 @@ else:
             # Use defaults when switching from another mode
             default_quality = "Medium (24kHz)" if "Medium (24kHz)" in quality_options else quality_options[0]
             saved_pwd = ''
-
-        quality_options = list(QUALITY_MAP.keys())
         if default_quality not in quality_options:
             default_quality = quality_options[0]
         quality = st.selectbox(