feat: Implement DeepSeek integration, refactor model adapters for streaming and tool calls, enhance admin and account management, and introduce new UI features for settings, API testing, and Vercel sync.

api/chat-stream/stream_emitter.js

@@ -0,0 +1,39 @@
+'use strict';
+
+function createChatCompletionEmitter({ res, sessionID, created, model, isClosed }) {
+  let firstChunkSent = false;
+
+  const sendFrame = (obj) => {
+    if (isClosed() || res.writableEnded || res.destroyed) {
+      return;
+    }
+    res.write(`data: ${JSON.stringify(obj)}\n\n`);
+    if (typeof res.flush === 'function') {
+      res.flush();
+    }
+  };
+
+  const sendDeltaFrame = (delta) => {
+    const payloadDelta = { ...delta };
+    if (!firstChunkSent) {
+      payloadDelta.role = 'assistant';
+      firstChunkSent = true;
+    }
+    sendFrame({
+      id: sessionID,
+      object: 'chat.completion.chunk',
+      created,
+      model,
+      choices: [{ delta: payloadDelta, index: 0 }],
+    });
+  };
+
+  return {
+    sendFrame,
+    sendDeltaFrame,
+  };
+}
+
+module.exports = {
+  createChatCompletionEmitter,
+};