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/schema.js

@@ -0,0 +1,57 @@
+import db from "./db.js";
+
+async function createUsersTable() {
+    await db.query(`
+        CREATE TABLE IF NOT EXISTS users (
+            id INT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
+            username VARCHAR(50) NOT NULL UNIQUE,
+            name VARCHAR(120) NOT NULL,
+            email VARCHAR(120) NOT NULL UNIQUE,
+            password_hash VARCHAR(255) NOT NULL,
+            created_at DATETIME DEFAULT CURRENT_TIMESTAMP
+        ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
+    `);
+}
+
+async function createLicensesTable() {
+    await db.query(`
+        CREATE TABLE IF NOT EXISTS licenses (
+            id CHAR(36) NOT NULL PRIMARY KEY,
+            user_id INT UNSIGNED NOT NULL,
+            license_key VARCHAR(64) NOT NULL UNIQUE,
+            label VARCHAR(255),
+            note TEXT,
+            repo_provider VARCHAR(32) NOT NULL,
+            repo_name VARCHAR(255) NOT NULL,
+            repo_base_url VARCHAR(255),
+            created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
+            updated_at DATETIME DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
+            last_version_check_at DATETIME NULL,
+            primary_hostname VARCHAR(255) NULL,
+            primary_hostname_normalized VARCHAR(255) NULL,
+            FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE
+        ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
+    `);
+}
+
+async function createLicenseHostnamesTable() {
+    await db.query(`
+        CREATE TABLE IF NOT EXISTS license_hostnames (
+            id INT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
+            license_id CHAR(36) NOT NULL,
+            hostname VARCHAR(255) NOT NULL,
+            normalized VARCHAR(255) NOT NULL,
+            first_seen_at DATETIME NOT NULL,
+            last_seen_at DATETIME NOT NULL,
+            hits INT UNSIGNED NOT NULL DEFAULT 1,
+            UNIQUE KEY unique_license_host (license_id, normalized),
+            FOREIGN KEY (license_id) REFERENCES licenses(id) ON DELETE CASCADE
+        ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
+    `);
+}
+
+export async function ensureSchema() {
+    await createUsersTable();
+    await createLicensesTable();
+    await createLicenseHostnamesTable();
+}