Initial commit: Deepwave Phase 1 - auth scaffolding

Spotify-like Navidrome client scaffold with Hilt DI, a Subsonic API
client (token auth, base-URL rewriting), encrypted single-server
credential storage (DataStore + Tink/Keystore), and a login/session
flow gating Compose Navigation between Login and a placeholder Home
screen.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

build.gradle.kts

@@ -0,0 +1,8 @@
+// Top-level build file where you can add configuration options common to all sub-projects/modules.
+plugins {
+    alias(libs.plugins.android.application) apply false
+    alias(libs.plugins.kotlin.compose) apply false
+    alias(libs.plugins.kotlin.serialization) apply false
+    alias(libs.plugins.ksp) apply false
+    alias(libs.plugins.hilt.android) apply false
+}