Fix display user not updating locally until app restart

Engines now read user.name from the config object at transcription time
instead of caching it at init, so name changes take effect immediately.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

client/deepgram_transcription.py

@@ -36,18 +36,16 @@ class DeepgramTranscriptionEngine:
     #  Construction / configuration
     # ------------------------------------------------------------------ #
 
-    def __init__(self, config, user_name: str = "User", input_device_index: Optional[int] = None):
+    def __init__(self, config, input_device_index: Optional[int] = None):
         """
         Initialise the engine from a :class:`client.config.Config` object.
 
         Args:
             config: Application ``Config`` instance.
-            user_name: Display name attached to transcriptions.
             input_device_index: Index of the audio input device to use
                 (``None`` for the system default).
         """
         self.config = config
-        self.user_name = user_name
         self.input_device_index = input_device_index
 
         # Mode: 'managed' (proxy) or 'byok' (direct Deepgram)
@@ -454,7 +452,7 @@ class DeepgramTranscriptionEngine:
                     text=text,
                     is_final=is_final,
                     timestamp=datetime.now(),
-                    user_name=self.user_name,
+                    user_name=self.config.get('user.name', 'User'),
                 )
                 if is_final:
                     if self.final_callback:
@@ -505,7 +503,7 @@ class DeepgramTranscriptionEngine:
                     text=transcript,
                     is_final=is_final,
                     timestamp=datetime.now(),
-                    user_name=self.user_name,
+                    user_name=self.config.get('user.name', 'User'),
                 )
                 if is_final:
                     if self.final_callback:
@@ -536,10 +534,6 @@ class DeepgramTranscriptionEngine:
                 pass
             self._ws = None
 
-    def set_user_name(self, user_name: str):
-        """Update the user name attached to future transcriptions."""
-        self.user_name = user_name
-
     def is_recording_active(self) -> bool:
         """Return ``True`` if audio is currently being captured."""
         return self._is_recording