chore: clean up voice channel code for MVP

- Simplify message builder content_attributes handling
- Remove AI captain integration from incoming call service
- Clean up FloatingCallWidget by removing non-essential features:
  - Remove Gravatar/MD5 dependency
  - Remove keypad/DTMF functionality
  - Remove fullscreen toggle
  - Simplify avatar handling
- Apply consistent code formatting across voice components
- Remove debug logging and unused code

🤖 Generated with [Claude Code](https://claude.ai/code)

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

app/javascript/dashboard/store/modules/inboxes.js

@@ -97,8 +97,7 @@ export const getters = {
   },
   getVoiceInboxes($state) {
     return $state.records.filter(
-      item =>
-        item.channel_type === INBOX_TYPES.VOICE
+      item => item.channel_type === INBOX_TYPES.VOICE
     );
   },
   dialogFlowEnabledInboxes($state) {
@@ -194,7 +193,7 @@ export const actions = {
   createVoiceChannel: async ({ commit }, params) => {
     try {
       commit(types.default.SET_INBOXES_UI_FLAG, { isCreating: true });
-      
+
       // Create a formatted payload for the voice channel
       const inboxParams = {
         name: params.voice.name || `Voice (${params.voice.phone_number})`,
@@ -205,10 +204,10 @@ export const actions = {
           provider_config: params.voice.provider_config,
         },
       };
-      
+
       // Use InboxesAPI to create the channel which handles authentication properly
       const response = await InboxesAPI.create(inboxParams);
-      
+
       commit(types.default.ADD_INBOXES, response.data);
       commit(types.default.SET_INBOXES_UI_FLAG, { isCreating: false });
       sendAnalyticsEvent('voice');