Initial commit: EGBE chatbot template

Stripped from vercel/chatbot (Apache 2.0):
- Dropped @vercel/* packages and AI Gateway
- Removed artifacts feature (code/text/sheet/image side panel)
- Switched AI provider to @ai-sdk/openai-compatible -> EGBE LiteLLM
- Replaced Vercel Blob upload with data URLs
- Dropped Redis resumable streams and rate limiter (in-memory now)
- Added Dockerfile (Next.js standalone) + entrypoint that runs migrations
- Wired DATABASE_URL, EGBE_AI_API_URL/KEY, NEXT_PUBLIC_BASE_URL for app-deploy.sh

app/(auth)/auth.ts

@@ -0,0 +1,99 @@
+import { compare } from "bcrypt-ts";
+import NextAuth, { type DefaultSession } from "next-auth";
+import type { DefaultJWT } from "next-auth/jwt";
+import Credentials from "next-auth/providers/credentials";
+import { DUMMY_PASSWORD } from "@/lib/constants";
+import { createGuestUser, getUser } from "@/lib/db/queries";
+import { authConfig } from "./auth.config";
+
+export type UserType = "guest" | "regular";
+
+declare module "next-auth" {
+  interface Session extends DefaultSession {
+    user: {
+      id: string;
+      type: UserType;
+    } & DefaultSession["user"];
+  }
+
+  interface User {
+    id?: string;
+    email?: string | null;
+    type: UserType;
+  }
+}
+
+declare module "next-auth/jwt" {
+  interface JWT extends DefaultJWT {
+    id: string;
+    type: UserType;
+  }
+}
+
+export const {
+  handlers: { GET, POST },
+  auth,
+  signIn,
+  signOut,
+} = NextAuth({
+  ...authConfig,
+  providers: [
+    Credentials({
+      credentials: {
+        email: { label: "Email", type: "email" },
+        password: { label: "Password", type: "password" },
+      },
+      async authorize(credentials) {
+        const email = String(credentials.email ?? "");
+        const password = String(credentials.password ?? "");
+        const users = await getUser(email);
+
+        if (users.length === 0) {
+          await compare(password, DUMMY_PASSWORD);
+          return null;
+        }
+
+        const [user] = users;
+
+        if (!user.password) {
+          await compare(password, DUMMY_PASSWORD);
+          return null;
+        }
+
+        const passwordsMatch = await compare(password, user.password);
+
+        if (!passwordsMatch) {
+          return null;
+        }
+
+        return { ...user, type: "regular" };
+      },
+    }),
+    Credentials({
+      id: "guest",
+      credentials: {},
+      async authorize() {
+        const [guestUser] = await createGuestUser();
+        return { ...guestUser, type: "guest" };
+      },
+    }),
+  ],
+  callbacks: {
+    jwt({ token, user }) {
+      if (user) {
+        token.id = user.id as string;
+        token.type = user.type;
+      }
+
+      return token;
+    },
+    session({ session, token }) {
+      if (session.user) {
+        session.user.id = token.id;
+        session.user.type = token.type;
+      }
+
+      return session;
+    },
+  },
+});