feat: implement user authentication and license management system

- Added schema for users, licenses, and license hostnames in the database.
- Created storage utility for reading and writing JSON files.
- Developed user service for user registration, authentication, and retrieval.
- Implemented authentication middleware to protect routes.
- Built LicenseCard component to display license details.
- Created SiteNav component for navigation with user authentication status.
- Established AuthContext for managing authentication state and actions.
- Developed Home page to display available plugins.
- Created LicenseManager page for managing licenses with forms for creation and verification.
- Implemented PluginDetail page to show detailed information about a specific plugin.
- Added utility functions for date formatting.

server/lib/storage.js

@@ -0,0 +1,19 @@
+import fs from "fs/promises";
+
+export async function readJsonFile(filePath, fallback = []) {
+    try {
+        const content = await fs.readFile(filePath, "utf-8");
+        const parsed = JSON.parse(content);
+        return parsed ?? fallback;
+    } catch (error) {
+        if (error.code === "ENOENT") {
+            await fs.writeFile(filePath, JSON.stringify(fallback, null, 2));
+            return fallback;
+        }
+        throw error;
+    }
+}
+
+export async function writeJsonFile(filePath, data) {
+    await fs.writeFile(filePath, JSON.stringify(data, null, 2));
+}