feat: refactor to SI Quiz with Space Invaders arcade interface

- Updated Dockerfile to Python 3.11, selective COPY for cleaner image
- Expanded .gitignore with Python/OS patterns
- Added config.json, questions.json, env_example, and static assets
- Updated templates (host, player, scores) with Space Invaders UI
- Rewrote README for SI Quiz branding and setup docs

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

docker-compose.yml

@@ -1,19 +1,38 @@
 services:
-  ni-quiz:
+  si-quiz:
     build: .
-    volumes:
-      - quiz-data:/data
-      - ./static:/app/static
-    environment:
-      - DB_PATH=/data/quiz.db
+    container_name: si-quiz
     restart: unless-stopped
+    ports:
+      - "8000:8000"
+    volumes:
+      - ./data:/data
+      - ./templates:/app/templates
+      - ./static:/app/static
+      - ./questions.json:/app/questions.json:ro
+      - ./config.json:/app/config.json:ro
+    environment:
+      - DB_PATH=${DB_PATH:-/data/si-quiz.db}
+      - CONFIG_PATH=${CONFIG_PATH:-config.json}
+      - QUESTIONS_PATH=${QUESTIONS_PATH:-questions.json}
     networks:
-      - web-net
-
-volumes:
-  quiz-data:
+      - si-quiz-net
 
 networks:
-  web-net:
-    external: true
-    name: web_web-net
+  si-quiz-net:
+    driver: bridge
+
+# ── REVERSE PROXY NOTE ────────────────────────────────────────────────────────
+# If you're using Caddy or nginx as a reverse proxy on the same Docker host,
+# connect the container to your shared proxy network and remove the ports block.
+# Example for Caddy (add to the si-quiz service):
+#
+#   networks:
+#     - si-quiz-net
+#     - web-net        # your Caddy shared network
+#
+# Caddyfile entry (no encode gzip — breaks WebSocket upgrade):
+#
+#   si-quiz.yourdomain.com {
+#     reverse_proxy si-quiz:8000
+#   }