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>

.gitignore

@@ -0,0 +1,37 @@
+# SSH keys (never commit!)
+android_studio
+android_studio.pub
+*.pem
+*.key
+id_rsa
+id_ed25519
+
+# Local configuration
+local.properties
+
+# Gradle build cache & outputs
+.gradle/
+build/
+**/build/
+
+# Android Studio / IntelliJ IDE generated files
+.idea/caches/
+.idea/libraries/
+.idea/modules.xml
+.idea/workspace.xml
+.idea/navEditor.xml
+.idea/assetWizardSettings.xml
+*.iml
+*.iws
+*.ipr
+
+# Generated files
+*.class
+*.ap_
+
+# Kotlin incremental compilation
+**/.kotlin/
+
+# OS junk
+.DS_Store
+Thumbs.db