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

docker-entrypoint.sh

@@ -0,0 +1,22 @@
+#!/bin/sh
+set -e
+
+if [ -n "$DATABASE_URL" ]; then
+  echo "==> Running database migrations"
+  node -e "
+    const { drizzle } = require('drizzle-orm/postgres-js');
+    const { migrate } = require('drizzle-orm/postgres-js/migrator');
+    const postgres = require('postgres');
+    (async () => {
+      const sql = postgres(process.env.DATABASE_URL, { max: 1 });
+      const db = drizzle(sql);
+      await migrate(db, { migrationsFolder: './lib/db/migrations' });
+      await sql.end();
+      console.log('Migrations completed');
+    })().catch((err) => { console.error('Migration failed:', err); process.exit(1); });
+  "
+else
+  echo "==> DATABASE_URL not set, skipping migrations"
+fi
+
+exec "$@"