Improve developer integration docs and Docker dev workflow.

Add TypeScript frontend integration documentation, repository agent guidance files, Go-served frontend routing, and an advanced Docker Compose setup with watch mode plus BuildKit cache configuration.

Made-with: Cursor

docker-compose.yml

@@ -3,6 +3,11 @@ services:
     build:
       context: .
       dockerfile: Dockerfile
+      target: runtime
+      cache_from:
+        - type=local,src=.docker/buildx-cache
+      cache_to:
+        - type=local,dest=.docker/buildx-cache,mode=max
     image: momswap-backend:latest
     container_name: momswap-backend-api
     environment:
@@ -11,7 +16,37 @@ services:
     ports:
       - "8080:8080"
     restart: unless-stopped
+
+  api-dev:
+    profiles: ["dev"]
+    build:
+      context: .
+      dockerfile: Dockerfile
+      target: dev
+      cache_from:
+        - type=local,src=.docker/buildx-cache
+      cache_to:
+        - type=local,dest=.docker/buildx-cache,mode=max
+    image: momswap-backend:dev
+    container_name: momswap-backend-api-dev
+    environment:
+      ADDR: ":8080"
+      ADMIN_PUBLIC_KEY: "${ADMIN_PUBLIC_KEY:-}"
+    ports:
+      - "8080:8080"
+    restart: unless-stopped
     develop:
       watch:
+        - action: sync+restart
+          path: ./web
+          target: /src/web
+        - action: sync+restart
+          path: ./internal
+          target: /src/internal
+        - action: sync+restart
+          path: ./cmd
+          target: /src/cmd
         - action: rebuild
-          path: .
+          path: ./go.mod
+        - action: rebuild
+          path: ./Dockerfile