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/proguard-rules.pro

@@ -0,0 +1,5 @@
+-dontwarn okhttp3.**
+-dontwarn okio.**
+-dontwarn javax.annotation.**
+-keep class com.mimo.studio.model.** { *; }
+-keep class com.mimo.studio.api.** { *; }