feat: MiMo Studio Android v1.0.0

- OpenAI-compatible API client for Xiaomi MiMo platform
- Chat completions with streaming support
- Model list browser
- Multi-conversation management
- Settings: API key, base URL, temperature, max tokens
- Material Design 3 UI

API Endpoints:
- GET  /v1/models          - List available models
- GET  /v1/models/{id}     - Get model details
- POST /v1/chat/completions - Chat (stream & non-stream)
- POST /v1/completions     - Text completions (stream & non-stream)

app/src/main/res/drawable/bg_user_bubble.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<shape xmlns:android="http://schemas.android.com/apk/res/android"
+    android:shape="rectangle">
+    <solid android:color="@color/mimo_user_bubble" />
+    <corners
+        android:topLeftRadius="16dp"
+        android:topRightRadius="16dp"
+        android:bottomLeftRadius="16dp"
+        android:bottomRightRadius="4dp" />
+</shape>