feat: multi-flavor APK build from dashboards.yaml

Dashboard URL and label configured in dashboards.yaml; each entry
becomes a product flavor with BuildConfig.DASHBOARD_URL injected
at build time. APKs output as <flavor>-release.apk.

README.md

@@ -1,23 +1,47 @@
 # android-webview-kiosk
 
-Fullscreen WebView kiosk for Android TV. Shows the house Grafana dashboard:
-<https://grafana.c3c.cz/public-dashboards/381fe3e71e164eb99dd0b10e246a36e2>
+Fullscreen WebView kiosk for Android TV. Shows configurable Grafana dashboards
+defined in `dashboards.yaml`. Target device: Sony Bravia KD-65XE9305 (Android 8.0).
+Built for remote launch via the Bravia REST IP-control API, driven by Control4.
 
-Target device: Sony Bravia KD-65XE9305 (Android 8.0). Built for remote
-launch via the Bravia REST IP-control API, driven by Control4.
+## Dashboards
+
+Defined in `dashboards.yaml` at repo root:
+
+```yaml
+weather:
+  url: https://grafana.c3c.cz/public-dashboards/...
+  label: Weather          # shown in Bravia launcher
+
+house_condition:
+  url: http://grafana.c3c.cz/public-dashboards/...
+  label: House Condition
+```
+
+Each entry produces a separate APK. Names must be valid Gradle identifiers
+(letters, digits, underscores — no hyphens).
 
 ## Build
 
+    # all flavors
     nix develop --command gradle --no-daemon :app:assembleRelease
 
-APK: `app/build/outputs/apk/release/app-release.apk`
+    # single flavor
+    nix develop --command gradle --no-daemon :app:assembleWeatherRelease
+
+APKs: `app/build/outputs/apk/<flavor>/release/<flavor>-release.apk`
 
 ## Sideload
 
 1. TV one-time: Settings → About → press *Build* 7× → Developer options →
    enable ADB debugging.
 2. `adb connect <tv-ip>:5555`
-3. `adb install -r app/build/outputs/apk/release/app-release.apk`
+3. `adb install -r app/build/outputs/apk/weather/release/weather-release.apk`
+
+Fresh install (removing old app first):
+
+    adb uninstall cz.c3c.webviewkiosk
+    adb install app/build/outputs/apk/<flavor>/release/<flavor>-release.apk
 
 Upgrades: bump `versionCode` in `app/build.gradle.kts`, rebuild, reinstall
 with `-r`. Same committed keystore = no uninstall needed.