Enhance voice interaction and transcript handling in the assistant

- Add a new Docker configuration for the UI in launch.json to facilitate development.
- Refactor pipeline.py to integrate a TranscriptProcessor for managing user and assistant transcripts, including event handlers for real-time updates and message handling.
- Update useVoicePreview.ts to establish a data channel for sending and receiving text messages, improving interaction flow.
- Modify AssistantPage.tsx to support displaying chat messages and sending user input, enhancing the user experience during voice interactions.
- Revise DebugTranscriptPanel to dynamically render chat messages with timestamps, improving the visual representation of conversation history.

.claude/launch.json

@@ -8,6 +8,13 @@
       "cwd": "frontend",
       "port": 3001,
       "autoPort": false
+    },
+    {
+      "name": "ui-docker",
+      "runtimeExecutable": "docker",
+      "runtimeArgs": ["compose", "up", "ui"],
+      "port": 3030,
+      "autoPort": false
     }
   ]
 }