feat: add database support, conversation sidebar, and improve chat streaming

- Update .gitignore to exclude database files, extensions, and .cursor directory
- Enhance chat streaming API with safe enqueue and close functions to prevent errors
- Integrate ConversationSidebar component into ClientHome for better UI
- Add dependencies like better-sqlite3 and esbuild packages for database functionality

This commit introduces database persistence for conversations, improves error handling in streaming responses, and adds a sidebar for managing chats, enhancing overall app robustness and user experience.

app/api/conversations/[id]/route.ts

@@ -0,0 +1,58 @@
+import { NextRequest, NextResponse } from "next/server";
+import { getDatabase } from "@/database/client";
+import { ConversationRepository } from "@/database/repositories/conversation";
+import { MessageRepository } from "@/database/repositories/message";
+
+export async function GET(
+  request: NextRequest,
+  { params }: { params: Promise<{ id: string }> }
+) {
+  try {
+    const { id } = await params;
+    const db = getDatabase();
+    const conversationRepo = new ConversationRepository(db);
+    const messageRepo = new MessageRepository(db);
+
+    const conversation = conversationRepo.findById(id);
+    if (!conversation) {
+      return NextResponse.json(
+        { error: "Conversa não encontrada" },
+        { status: 404 }
+      );
+    }
+
+    const messages = messageRepo.findByConversation(id);
+
+    return NextResponse.json({
+      conversation,
+      messages,
+    });
+  } catch (error) {
+    console.error("Erro ao buscar conversa:", error);
+    return NextResponse.json(
+      { error: "Erro interno do servidor" },
+      { status: 500 }
+    );
+  }
+}
+
+export async function DELETE(
+  request: NextRequest,
+  { params }: { params: Promise<{ id: string }> }
+) {
+  try {
+    const { id } = await params;
+    const db = getDatabase();
+    const conversationRepo = new ConversationRepository(db);
+
+    conversationRepo.delete(id);
+
+    return NextResponse.json({ success: true });
+  } catch (error) {
+    console.error("Erro ao deletar conversa:", error);
+    return NextResponse.json(
+      { error: "Erro interno do servidor" },
+      { status: 500 }
+    );
+  }
+}