feat(icons): add macOS and Android icons for application branding (#75)

- Updated `tauri.macos.conf.json` to include the application icon.
- Added various icon sizes for macOS and Android platforms, including .png, .icns, and .ico formats.
- Introduced adaptive launcher XML for Android and background color resource for launcher consistency.

src-tauri/icons-macos/android/mipmap-anydpi-v26/ic_launcher.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+  <foreground android:drawable="@mipmap/ic_launcher_foreground"/>
+  <background android:drawable="@color/ic_launcher_background"/>
+</adaptive-icon>

src-tauri/icons-macos/android/values/ic_launcher_background.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+  <color name="ic_launcher_background">#fff</color>
+</resources>

src-tauri/tauri.macos.conf.json

@@ -20,6 +20,9 @@
       "entitlements": "packages/macos/Entitlements.plist",
       "infoPlist": "packages/macos/Info.plist",
       "signingIdentity": "-"
-    }
+    },
+    "icon": [
+      "icons-macos/icon.icns"
+    ]
   }
 }