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

lib/constants.ts

@@ -0,0 +1,20 @@
+import { generateDummyPassword } from "./db/utils";
+
+export const isProductionEnvironment = process.env.NODE_ENV === "production";
+export const isDevelopmentEnvironment = process.env.NODE_ENV === "development";
+export const isTestEnvironment = Boolean(
+  process.env.PLAYWRIGHT_TEST_BASE_URL ||
+    process.env.PLAYWRIGHT ||
+    process.env.CI_PLAYWRIGHT
+);
+
+export const guestRegex = /^guest-\d+$/;
+
+export const DUMMY_PASSWORD = generateDummyPassword();
+
+export const suggestions = [
+  "What are the advantages of using Next.js?",
+  "Write code to demonstrate Dijkstra's algorithm",
+  "Help me write an essay about Silicon Valley",
+  "What is the weather in San Francisco?",
+];