feat: Enhance UserScript structure and functionality

- Updated package.json to include new scripts for development, production builds, linting, formatting, and cleaning.
- Added ESLint and Prettier for code quality and formatting.
- Refactored main application class to extend EventEmitter and manage modules.
- Introduced ExampleModule to demonstrate module structure and functionality.
- Created utility classes for DOM manipulation, event handling, and persistent storage.
- Added TypeScript definitions for UserScript environment.
- Improved TypeScript configuration with stricter checks and path aliases.
- Updated Vite configuration to handle development and production builds more effectively.
- Enhanced user script header generation to support environment-specific configurations.

src/utils/events.ts

@@ -0,0 +1,78 @@
+/**
+ * Type-safe event emitter for UserScript modules
+ */
+export interface EventMap {
+  [event: string]: any;
+}
+
+export class EventEmitter<T extends EventMap = EventMap> {
+  private listeners: { [K in keyof T]?: Array<(data: T[K]) => void> } = {};
+
+  /**
+   * Add event listener
+   */
+  on<K extends keyof T>(event: K, listener: (data: T[K]) => void): void {
+    if (!this.listeners[event]) {
+      this.listeners[event] = [];
+    }
+    this.listeners[event]!.push(listener);
+  }
+
+  /**
+   * Add one-time event listener
+   */
+  once<K extends keyof T>(event: K, listener: (data: T[K]) => void): void {
+    const onceListener = (data: T[K]) => {
+      listener(data);
+      this.off(event, onceListener);
+    };
+    this.on(event, onceListener);
+  }
+
+  /**
+   * Remove event listener
+   */
+  off<K extends keyof T>(event: K, listener: (data: T[K]) => void): void {
+    const eventListeners = this.listeners[event];
+    if (eventListeners) {
+      const index = eventListeners.indexOf(listener);
+      if (index > -1) {
+        eventListeners.splice(index, 1);
+      }
+    }
+  }
+
+  /**
+   * Emit event
+   */
+  emit<K extends keyof T>(event: K, data: T[K]): void {
+    const eventListeners = this.listeners[event];
+    if (eventListeners) {
+      eventListeners.forEach(listener => {
+        try {
+          listener(data);
+        } catch (error) {
+          console.error(`Error in event listener for "${String(event)}":`, error);
+        }
+      });
+    }
+  }
+
+  /**
+   * Remove all listeners for an event
+   */
+  removeAllListeners<K extends keyof T>(event?: K): void {
+    if (event) {
+      delete this.listeners[event];
+    } else {
+      this.listeners = {};
+    }
+  }
+
+  /**
+   * Get listener count for an event
+   */
+  listenerCount<K extends keyof T>(event: K): number {
+    return this.listeners[event]?.length || 0;
+  }
+}