feat(infra): add frontend service to compose for one-command local stack

README.md

@@ -159,16 +159,22 @@ npm run dev:frontend
 
 Open `http://localhost:5173`, register a local account, add a repository, and start analysis.
 
-### Optional: local Compose stack
+### Optional: local Compose stack (recommended for local dev)
 
-Compose runs the API with PostgreSQL and Redis for local development. It is not production deployment guidance.
+Compose runs the full stack — API, PostgreSQL, Redis, and the frontend dev
+server — in one command. It is not production deployment guidance.
 
 ```bash
-npm run docker:config
-npm run docker:up
+npm run docker:config   # validate the compose file
+npm run docker:up        # build and start api + postgres + redis + frontend
 ```
 
-Run the frontend separately with `npm run dev:frontend`. See the [AI provider egress policy](docs/security/AI_PROVIDER_EGRESS.md) before configuring any custom or local provider endpoint.
+The frontend dev server is available at `http://localhost:5173` and talks to
+the API container over the internal network. Source is mounted, so edits hot
+reload. See the [AI provider egress policy](docs/security/AI_PROVIDER_EGRESS.md)
+before configuring any custom or local provider endpoint.
+
+To run the frontend outside Compose instead, use `npm run dev:frontend`.
 
 ## Verification
 

apps/frontend/Dockerfile

@@ -0,0 +1,19 @@
+# Development image for the PARTHA frontend.
+# Runs the Vite dev server so `docker compose up` brings up the whole stack
+# (api + postgres + redis + frontend) in one command. Hot reload works because
+# the compose service mounts the source directory.
+FROM node:20-alpine
+
+WORKDIR /app
+
+# Install dependencies first for better layer caching.
+COPY package.json package-lock.json ./
+RUN npm install
+
+# Vite must bind to 0.0.0.0 inside the container so the published port is
+# reachable from the host. The frontend reaches the backend by its compose
+# service name (http://api:8000), not localhost.
+ENV VITE_API_URL=http://api:8000
+EXPOSE 5173
+
+CMD ["npm", "run", "dev", "--", "--host", "0.0.0.0", "--port", "5173"]

docker-compose.yml

@@ -50,6 +50,25 @@ services:
       - data
       - egress
 
+  frontend:
+    build:
+      context: ./apps/frontend
+      dockerfile: Dockerfile
+    ports:
+      - "5173:5173"
+    environment:
+      # Reach the backend by its compose service name, not localhost.
+      VITE_API_URL: http://api:8000
+    # Mount source for hot reload; keep the container's node_modules.
+    volumes:
+      - ./apps/frontend:/app
+      - /app/node_modules
+    depends_on:
+      api:
+        condition: service_started
+    networks:
+      - data
+
   postgres:
     image: postgres:16-alpine
     environment: