feat(bridge): add wifi/serial bridge runtime and UI

Co-authored-by: Cursor <cursoragent@cursor.com>

src/settings.py

@@ -2,6 +2,8 @@ import json
 import os
 import binascii
 
+WIFI_CHANNEL_DEFAULT = 5
+
 
 def _settings_path():
     """Path to settings.json in project root (writable without root)."""
@@ -51,10 +53,20 @@ class Settings(dict):
             self.save()
         # ESP-NOW STA channel (2.4 GHz) for LED drivers / bridge alignment; 1–11
         if 'wifi_channel' not in self:
-            self['wifi_channel'] = 1
+            self['wifi_channel'] = WIFI_CHANNEL_DEFAULT
         # WebSocket URL of ESP-NOW bridge (Pi is client), e.g. ws://192.168.4.1/ws
         if 'bridge_ws_url' not in self:
             self['bridge_ws_url'] = ''
+        if 'wifi_interface' not in self:
+            self['wifi_interface'] = ''
+        if 'bridges' not in self:
+            self['bridges'] = []
+        if 'bridge_transport' not in self:
+            self['bridge_transport'] = 'serial'
+        if 'bridge_serial_port' not in self:
+            self['bridge_serial_port'] = ''
+        if 'bridge_serial_baudrate' not in self:
+            self['bridge_serial_baudrate'] = 115200
         # Zone UI global brightness (0–255); shared across browsers/devices.
         if 'global_brightness' not in self:
             self['global_brightness'] = 255
@@ -66,6 +78,9 @@ class Settings(dict):
         # Beat flash alignment delay (ms); applied by all UI clients polling audio status.
         if 'audio_beat_phase_ms' not in self:
             self['audio_beat_phase_ms'] = 0
+        # Input gain for beat detection (percent, 0–200).
+        if 'audio_input_volume' not in self:
+            self['audio_input_volume'] = 100
 
     def save(self):
         try: