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/ai/models.test.ts

@@ -0,0 +1,67 @@
+import type { LanguageModelV3GenerateResult } from "@ai-sdk/provider";
+import { simulateReadableStream } from "ai";
+import { MockLanguageModelV3 } from "ai/test";
+import { getResponseChunksByPrompt } from "@/tests/prompts/utils";
+
+const mockUsage = {
+  inputTokens: { total: 10, noCache: 10, cacheRead: 0, cacheWrite: 0 },
+  outputTokens: { total: 20, text: 20, reasoning: 0 },
+};
+
+const mockFinishReason = { unified: "stop" as const, raw: undefined };
+
+const mockGenerateResult: LanguageModelV3GenerateResult = {
+  finishReason: mockFinishReason,
+  usage: mockUsage,
+  content: [{ type: "text", text: "Hello, world!" }],
+  warnings: [],
+};
+
+const titleGenerateResult: LanguageModelV3GenerateResult = {
+  finishReason: mockFinishReason,
+  usage: mockUsage,
+  content: [{ type: "text", text: "This is a test title" }],
+  warnings: [],
+};
+
+export const chatModel = new MockLanguageModelV3({
+  doGenerate: mockGenerateResult,
+  doStream: async ({ prompt }) => ({
+    stream: simulateReadableStream({
+      chunkDelayInMs: 500,
+      initialDelayInMs: 1000,
+      chunks: getResponseChunksByPrompt(prompt),
+    }),
+  }),
+});
+
+export const reasoningModel = new MockLanguageModelV3({
+  doGenerate: mockGenerateResult,
+  doStream: async ({ prompt }) => ({
+    stream: simulateReadableStream({
+      chunkDelayInMs: 500,
+      initialDelayInMs: 1000,
+      chunks: getResponseChunksByPrompt(prompt, true),
+    }),
+  }),
+});
+
+export const titleModel = new MockLanguageModelV3({
+  doGenerate: titleGenerateResult,
+  doStream: async () => ({
+    stream: simulateReadableStream({
+      chunkDelayInMs: 500,
+      initialDelayInMs: 1000,
+      chunks: [
+        { id: "1", type: "text-start" as const },
+        { id: "1", type: "text-delta" as const, delta: "This is a test title" },
+        { id: "1", type: "text-end" as const },
+        {
+          type: "finish" as const,
+          finishReason: mockFinishReason,
+          usage: mockUsage,
+        },
+      ],
+    }),
+  }),
+});