refactor: move lib directory to libs for consistency

- Move src/lib/capacitor to src/libs/capacitor
- Move src/lib/fontawesome.ts to src/libs/fontawesome.ts
- Update import paths in main.capacitor.ts and main.common.ts
- Remove empty src/lib directory

This change standardizes the project structure by using the 'libs'
directory consistently throughout the codebase.

src/libs/capacitor/app.ts

@@ -0,0 +1,59 @@
+// Import from node_modules using relative path
+
+import {
+  App as CapacitorApp,
+  AppLaunchUrl,
+  BackButtonListener,
+} from "../../../node_modules/@capacitor/app";
+import type { PluginListenerHandle } from "@capacitor/core";
+
+/**
+ * Interface defining the app event listener functionality
+ * Supports 'backButton' and 'appUrlOpen' events from Capacitor
+ */
+interface AppInterface {
+  /**
+   * Add listener for back button events
+   * @param eventName - Must be 'backButton'
+   * @param listenerFunc - Callback function for back button events
+   * @returns Promise that resolves with a removable listener handle
+   */
+  addListener(
+    eventName: "backButton",
+    listenerFunc: BackButtonListener,
+  ): Promise<PluginListenerHandle> & PluginListenerHandle;
+
+  /**
+   * Add listener for app URL open events
+   * @param eventName - Must be 'appUrlOpen'
+   * @param listenerFunc - Callback function for URL open events
+   * @returns Promise that resolves with a removable listener handle
+   */
+  addListener(
+    eventName: "appUrlOpen",
+    listenerFunc: (data: AppLaunchUrl) => void,
+  ): Promise<PluginListenerHandle> & PluginListenerHandle;
+}
+
+/**
+ * App wrapper for Capacitor functionality
+ * Provides type-safe event listeners for back button and URL open events
+ */
+export const App: AppInterface = {
+  addListener(
+    eventName: "backButton" | "appUrlOpen",
+    listenerFunc: BackButtonListener | ((data: AppLaunchUrl) => void),
+  ): Promise<PluginListenerHandle> & PluginListenerHandle {
+    if (eventName === "backButton") {
+      return CapacitorApp.addListener(
+        eventName,
+        listenerFunc as BackButtonListener,
+      ) as Promise<PluginListenerHandle> & PluginListenerHandle;
+    } else {
+      return CapacitorApp.addListener(
+        eventName,
+        listenerFunc as (data: AppLaunchUrl) => void,
+      ) as Promise<PluginListenerHandle> & PluginListenerHandle;
+    }
+  },
+};