feat: add settings table and backup notification functionality

migrate-add-settings-table.mjs

@@ -0,0 +1,25 @@
+import db from "./src/lib/db.js";
+
+console.log("Adding settings table...");
+
+try {
+    db.exec(`
+        CREATE TABLE IF NOT EXISTS settings (
+            key TEXT PRIMARY KEY,
+            value TEXT NOT NULL,
+            description TEXT,
+            updated_at TEXT DEFAULT CURRENT_TIMESTAMP,
+            updated_by TEXT,
+            FOREIGN KEY (updated_by) REFERENCES users(id)
+        );
+    `);
+
+    db.exec(`
+        INSERT OR IGNORE INTO settings (key, value, description) VALUES 
+        ('backup_notification_user_id', '', 'User ID to receive backup completion notifications');
+    `);
+
+    console.log("✅ Settings table created successfully");
+} catch (error) {
+    console.error("Error creating settings table:", error);
+}