chore: add project scaffolding and resources

This initial commit scaffolds the project with essential docs, assets, and build configs.
It adds Android icons, design assets, and release metadata to support mobile targets.
A fastlane config and F-Droid manifest are included to streamline builds.

- Adds F-Droid configuration for automated builds
- Includes license and privacy policy documents
- Provides app icons and assets for Android and design system

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

@@ -1,5 +1,6 @@
 <?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>
+  <background android:drawable="@mipmap/ic_launcher_background"/>
+  <monochrome android:drawable="@mipmap/ic_launcher_monochrome"/>
+</adaptive-icon>

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

@@ -1,4 +1,4 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
-  <color name="ic_launcher_background">#fff</color>
-</resources>
+  <color name="ic_launcher_background">#EDF4E9</color>
+</resources>