Initial commit: Kecalek Android client

Complete Android client for encrypted chat platform.
78+ Kotlin files: crypto (X3DH, Double Ratchet, AES-GCM, Ed25519, X25519,
RSA-PSS), network (TCP/TLS, 50 endpoints), Hilt DI, Room+SQLCipher DB,
Jetpack Compose UI with Catppuccin Mocha theme.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.idea/migrations.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectMigrations">
+    <option name="MigrateToGradleLocalJavaHome">
+      <set>
+        <option value="$PROJECT_DIR$" />
+      </set>
+    </option>
+  </component>
+</project>