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>

CLAUDE.md

@@ -1,6 +1,6 @@
 # btcprice
 
-Bitcoin price tracker UI — Clojure Kit web application. Serves the HTML/HTMX/Tailwind UI. Connects to btcdata for live price data via SSE.
+Bitcoin price tracker UI — Clojure Kit web application. Serves the HTML/Tailwind UI. Connects to btcdata for live price data via SSE.
 
 ## Build & Development Commands
 
@@ -9,6 +9,18 @@ Bitcoin price tracker UI — Clojure Kit web application. Serves the HTML/HTMX/T
 - `make test` — Run tests
 - `make tailwind` — Watch Tailwind CSS for changes
 - `make uberjar` — Build production JAR
+- `docker compose up -d` — Start btcprice + btcdata containers
+
+## Docker
+
+Docker runs alongside local dev on different ports:
+
+| Service  | Local dev      | Docker         |
+|----------|----------------|----------------|
+| btcprice | localhost:4000 | localhost:4041 |
+| btcdata  | localhost:4100 | localhost:4101 |
+
+btcprice's docker-compose includes btcdata via `include: ../btcdata/docker-compose.yml`.
 
 ## REPL Commands
 

README.md

@@ -0,0 +1,32 @@
+# btcprice
+
+Bitcoin price tracker UI. Serves an HTML page with live price updates streamed from [btcdata](../btcdata) via Server-Sent Events.
+
+## Quick Start
+
+```bash
+# Start btcdata first (provides price data)
+cd ../btcdata && make run
+
+# Local dev
+make run       # starts on port 4000
+make tailwind  # watch Tailwind CSS (separate terminal)
+
+# Docker (starts both btcprice + btcdata)
+docker compose up -d   # btcprice on 4041, btcdata on 4101
+```
+
+## Environment Variables
+
+| Variable | Default | Description |
+|---|---|---|
+| `PORT` | `4000` | HTTP server port |
+| `BTCDATA_URL` | `http://localhost:4100` | btcdata service URL (injected into browser JS) |
+
+## How It Works
+
+The server renders an HTML page that includes a vanilla JavaScript `EventSource` connecting directly to btcdata's SSE endpoint (`BTCDATA_URL/api/price/stream`). Price updates are rendered client-side with color-coded changes (green up, red down).
+
+## Tech Stack
+
+Clojure · Kit · Undertow · Reitit · Hiccup · Tailwind CSS v4

docker-compose.yml

@@ -1,22 +1,11 @@
-services:
+include:
-  btcdata:
+  - path: ../btcdata/docker-compose.yml
-    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"
 
-  app:
+services:
+  btcprice:
     build: .
     restart: unless-stopped
     ports:
-      - "4040:4040"
+      - "4041:4040"
     environment:
-      BTCDATA_URL: "http://btcdata:4100"
+      BTCDATA_URL: "http://localhost:4101"
-    depends_on:
-      - btcdata