Initial commit: Pezkuwi Wallet Android

Security hardened release:
- Code obfuscation enabled (minifyEnabled=true, shrinkResources=true)
- Sensitive files excluded (google-services.json, keystores)
- Branch.io key moved to BuildConfig placeholder
- Updated dependencies: OkHttp 4.12.0, Gson 2.10.1, BouncyCastle 1.77
- Comprehensive ProGuard rules for crypto wallet
- Navigation 2.7.7, Lifecycle 2.7.0, ConstraintLayout 2.1.4

common/src/main/res/font/public_sans.xml

@@ -0,0 +1,28 @@
+<?xml version="1.0" encoding="utf-8"?>
+<font-family xmlns:app="http://schemas.android.com/apk/res-auto">
+    <font
+        app:font="@font/public_sans_extra_light"
+        app:fontStyle="normal"
+        app:fontWeight="200" />
+
+    <font
+        app:font="@font/public_sans_regular"
+        app:fontStyle="normal"
+        app:fontWeight="400" />
+
+    <font
+        app:font="@font/public_sans_semi_bold"
+        app:fontStyle="normal"
+        app:fontWeight="600" />
+
+    <font
+        app:font="@font/public_sans_bold"
+        app:fontStyle="normal"
+        app:fontWeight="700" />
+
+    <font
+        app:font="@font/public_sans_extra_bold"
+        app:fontStyle="normal"
+        app:fontWeight="800" />
+
+</font-family>