Add Spring Boot Twitch overlay server with CI and Docker

README.md

@@ -1 +1,54 @@
 # Imgfloat
+
+A Spring Boot overlay server for Twitch broadcasters and their channel admins. Broadcasters can authorize via Twitch OAuth and invite channel admins to manage images that float over a transparent canvas. Updates are pushed in real time over WebSockets so OBS browser sources stay in sync.
+
+## Features
+- Twitch OAuth (OAuth2 login) with broadcaster and channel admin access controls.
+- Admin console with Twitch player embed and canvas preview.
+- Broadcaster overlay view optimized for OBS browser sources.
+- Real-time image creation, movement, resize, rotation, visibility toggles, and deletion via STOMP/WebSockets.
+- In-memory channel directory optimized with lock-free collections for fast updates.
+- Optional SSL with local self-signed keystore support.
+- Dockerfile, Makefile, CI workflow, and Maven build.
+
+## Getting started
+### Prerequisites
+- Java 17+
+- Maven 3.9+
+- Twitch Developer credentials (Client ID/Secret)
+
+### Local run
+```bash
+TWITCH_CLIENT_ID=your_id TWITCH_CLIENT_SECRET=your_secret mvn spring-boot:run
+```
+The default server port is `8080`. Log in via `/oauth2/authorization/twitch`.
+
+### Enable TLS locally
+```bash
+make ssl
+SSL_ENABLED=true SSL_KEYSTORE_PATH=file:$(pwd)/local/keystore.p12 \
+TWITCH_CLIENT_ID=your_id TWITCH_CLIENT_SECRET=your_secret \
+mvn spring-boot:run -Dspring-boot.run.arguments="--server.port=8443"
+```
+
+### Make targets
+- `make run` – start the dev server.
+- `make test` – run unit/integration tests.
+- `make package` – build the runnable jar.
+- `make docker-build` / `make docker-run` – containerize and run the service.
+- `make ssl` – create a self-signed PKCS12 keystore in `./local`.
+
+### Docker
+```bash
+make docker-build
+TWITCH_CLIENT_ID=your_id TWITCH_CLIENT_SECRET=your_secret docker run -p 8080:8080 imgfloat:latest
+```
+
+### OAuth configuration
+Spring Boot reads Twitch credentials from `TWITCH_CLIENT_ID` and `TWITCH_CLIENT_SECRET`. The redirect URI is `{baseUrl}/login/oauth2/code/twitch`.
+
+### CI
+GitHub Actions runs `mvn verify` on pushes and pull requests via `.github/workflows/ci.yml`.
+
+### License
+MIT