feat(assets): Add comprehensive platform icon assets

This update introduces a complete set of high-resolution icons for all target platforms. This ensures consistent branding and visual identity across desktop, Android, and iOS environments. The tauri configuration file has been updated to utilize these new assets.

- Added full sets of Android mipmap density icons
- Included comprehensive iOS AppIcon assets for multiple sizes
- Updated tauri.conf.json with modern icon paths

src-tauri/icons/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/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>