Fix outdated README and defer self-hosting docs to implementation

- Remove aspirational self-hosting section (docker-compose, config table,
  image storage) — will be written when features are actually implemented
- Fix build commands: mvn → ./mvnw, npm test → npm run test:unit
- Remove nonexistent Dockerfile from project structure tree
- Remove Testcontainers from prerequisites (not yet a dependency)
- Add README documentation ACs to US-13 (MAX_ACTIVE_EVENTS) and US-16
  (UNSPLASH_API_KEY + volume mount)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

README.md

@@ -41,71 +41,12 @@ A privacy-focused, self-hostable web app for event announcements and RSVPs. An a
 | Architecture | SPA + RESTful API, hexagonal/onion backend |
 | Deployment   | Single Docker container                    |
 
-## Self-hosting
-
-### Prerequisites
-
-- Docker and Docker Compose
-- A PostgreSQL instance (self-hosted or managed)
-
-### Quick start
-
-```yaml
-# docker-compose.yml
-services:
-  fete:
-    image: fete:latest
-    ports:
-      - "8080:8080"
-    environment:
-      DATABASE_URL: "jdbc:postgresql://db:5432/fete"
-      # Optional: limit simultaneous active events
-      # MAX_ACTIVE_EVENTS: 100
-      # Optional: enable Unsplash image search for event headers
-      # UNSPLASH_API_KEY: your-api-key
-    depends_on:
-      - db
-
-  db:
-    image: postgres:17
-    environment:
-      POSTGRES_DB: fete
-      POSTGRES_USER: fete
-      POSTGRES_PASSWORD: changeme
-    volumes:
-      - pgdata:/var/lib/postgresql/data
-
-volumes:
-  pgdata:
-```
-
-```bash
-docker compose up -d
-```
-
-The app runs at `http://localhost:8080`. Database migrations run automatically on startup.
-
-### Configuration
-
-All configuration is done via environment variables:
-
-| Variable            | Required | Description                                                                                                                 |
-|---------------------|----------|-----------------------------------------------------------------------------------------------------------------------------|
-| `DATABASE_URL`      | Yes      | JDBC connection string for PostgreSQL                                                                                       |
-| `MAX_ACTIVE_EVENTS` | No       | Maximum number of non-expired events. Unset = unlimited                                                                     |
-| `UNSPLASH_API_KEY`  | No       | Enables header image search via Unsplash. Images are fetched server-side and stored locally — guests never contact Unsplash |
-
-### Image storage
-
-If you use the Unsplash header image feature, mount a persistent volume for stored images so they survive container restarts. The exact path will be documented once the feature is implemented.
-
 ## Development
 
 ### Prerequisites
 
-- Java (latest LTS) + Maven
+- Java (latest LTS) + Maven wrapper (`./mvnw`, included)
 - Node.js (latest LTS) + npm
-- PostgreSQL (or Docker for Testcontainers)
 
 ### Project structure
 
@@ -114,25 +55,24 @@ fete/
 ├── backend/      # Spring Boot application (Maven)
 ├── frontend/     # Vue 3 SPA (Vite, TypeScript)
 ├── spec/         # User stories, personas, implementation phases
-├── Dockerfile    # Multi-stage build for production
 └── CLAUDE.md     # Project statutes and AI agent instructions
 ```
 
 ### Running tests
 
 ```bash
-# Backend (uses Testcontainers — needs Docker running)
-cd backend && mvn test
+# Backend
+cd backend && ./mvnw test
 
 # Frontend
-cd frontend && npm test
+cd frontend && npm run test:unit
 ```
 
 ### Building
 
 ```bash
 # Backend
-cd backend && mvn package
+cd backend && ./mvnw package
 
 # Frontend
 cd frontend && npm run build