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>

app/src/main/java/com/InfernalAquatics/deepwave/MainActivity.kt

@@ -0,0 +1,22 @@
+package com.InfernalAquatics.deepwave
+
+import android.os.Bundle
+import androidx.activity.ComponentActivity
+import androidx.activity.compose.setContent
+import androidx.activity.enableEdgeToEdge
+import com.InfernalAquatics.deepwave.ui.navigation.DeepwaveNavHost
+import com.InfernalAquatics.deepwave.ui.theme.DeepwaveTheme
+import dagger.hilt.android.AndroidEntryPoint
+
+@AndroidEntryPoint
+class MainActivity : ComponentActivity() {
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        enableEdgeToEdge()
+        setContent {
+            DeepwaveTheme {
+                DeepwaveNavHost()
+            }
+        }
+    }
+}