Add README, update docker-compose and CLAUDE.md

Docker runs on port 4041 alongside local dev on 4000.
Include btcdata docker-compose for unified startup.

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

docker-compose.yml

@@ -1,22 +1,11 @@
-services:
-  btcdata:
-    build: ../btcdata
-    restart: unless-stopped
-    ports:
-      - "4100:4100"
-    environment:
-      BTCDATA_PORT: "4100"
-      JDBC_URL: "jdbc:postgresql://postgres:5432/btcprod?user=postgres&password=ratata,123"
-      CORS_ORIGIN: "http://localhost:4040"
-    extra_hosts:
-      - "postgres:host-gateway"
+include:
+  - path: ../btcdata/docker-compose.yml
 
-  app:
+services:
+  btcprice:
     build: .
     restart: unless-stopped
     ports:
-      - "4040:4040"
+      - "4041:4040"
     environment:
-      BTCDATA_URL: "http://btcdata:4100"
-    depends_on:
-      - btcdata
+      BTCDATA_URL: "http://localhost:4101"