memory service schema added

packages/memory-service/src/db/index.js

@@ -0,0 +1,23 @@
+const Database = require('better-sqlite3');
+const schema = require('./schema');
+const {getEnv } = require('@nexusai/shared');
+
+let db;  // Declare db variable in a scope accessible to all functions
+
+function getDB() {
+    if (!db) {
+        const path = getEnv('SQLITE_PATH', './data/nexusai.db');
+        db = new Database(path);
+
+        db.pragma('journal_mode = WAL');
+        db.pragma('foreign_keys = ON');
+
+        db.exec(schema);
+        console.log(`Connected to SQLite database at ${path}`);
+    }
+    return db;
+}
+
+module.exports = {
+    getDB
+};