feat: initial project scaffold — server, client, Android APK

- FastAPI server with audio mixer (Windows + Voicemeeter), media tracking,
  notifications (progress + alerts), telemetry, and system tray .exe build
- Test suite covering notifications, audio mixer, media, telemetry, and API
- E-Ink web client (vanilla JS, DOM API, block meters, swipe gestures)
- Android WebView APK for BOOX Go 7 Color Gen II (Android 13, Kotlin)
- Design decision records in .pi/docs/design/
- PyInstaller build script for server .exe

android/README.md

@@ -0,0 +1,103 @@
+# PaperDash Android Client
+
+WebView-based Android app for the **BOOX Go 7 Color (Gen II)** running Android 13.
+
+## Project Structure
+
+```
+android/
+├── app/
+│   ├── src/main/
+│   │   ├── assets/           # Bundled HTML/CSS/JS (served from file://)
+│   │   │   ├── index.html
+│   │   │   ├── style.css
+│   │   │   └── app.js
+│   │   ├── java/.../paperdash/
+│   │   │   └── MainActivity.kt   # WebView container
+│   │   ├── res/
+│   │   │   ├── layout/activity_main.xml
+│   │   │   └── values/themes.xml
+│   │   └── AndroidManifest.xml
+│   ├── build.gradle.kts
+│   └── proguard-rules.pro
+├── build.gradle.kts
+├── settings.gradle.kts
+└── gradle.properties
+```
+
+## Build Requirements
+
+- **Android Studio** (Hedgehog or newer) with Android SDK
+- **Android 13 SDK** (API 33) or newer
+- **JDK 17**
+
+## Building
+
+### Option 1: Android Studio
+
+1. Open `android/` in Android Studio
+2. Sync Gradle
+3. Run on connected BOOX device or emulator
+
+### Option 2: Command Line
+
+```bash
+cd android
+./gradlew assembleDebug
+# APK at: app/build/outputs/apk/debug/app-debug.apk
+```
+
+### Release Build
+
+```bash
+./gradlew assembleRelease
+# APK at: app/build/outputs/apk/release/app-release-unsigned.apk
+```
+
+## Installation on BOOX Go 7 Color
+
+1. Enable **Developer Options** on the BOOX (tap Build Number 7 times in Settings)
+2. Enable **USB Debugging** in Developer Options
+3. Connect via USB and run:
+
+   ```bash
+   adb install app/build/outputs/apk/debug/app-debug.apk
+   ```
+
+4. Or transfer the APK via file manager and install directly
+
+## Architecture
+
+The app is a thin WebView container:
+
+1. **MainActivity** loads `file:///android_asset/index.html`
+2. **WebView** connects to the PaperDash server via WebSocket (`ws://<pc-ip>:8921/ws`)
+3. The server pushes real-time state (media, audio, telemetry, notifications)
+4. System bars are hidden for full-screen E-Ink display
+
+## Key Configuration
+
+- **minSdk: 33** (Android 13) — matches BOOX Go 7 Color Gen II
+- **targetSdk: 34** (Android 14)
+- **compileSdk: 34**
+- **Orientation: landscape** (optimized for the 7" display)
+- **Full-screen immersive mode** — hides status and navigation bars
+- **JavaScript enabled** — required for WebSocket connection
+- **No smooth scrolling** — prevents E-Ink refresh artifacts
+
+## Updating the Client
+
+The HTML/CSS/JS files live in `android/app/src/main/assets/`. To update:
+
+1. Edit files in `client/` (source of truth)
+2. Copy to `android/app/src/main/assets/`:
+
+   ```bash
+   cp client/index.html android/app/src/main/assets/
+   cp client/style.css android/app/src/main/assets/
+   cp client/app.js android/app/src/main/assets/
+   ```
+
+3. Rebuild the APK
+
+Alternatively, the WebView can be configured to load from the server URL instead of local assets — see `MainActivity.kt` line where `loadUrl` is called.