feat: add Docker deployment and application configuration

Add package declarations across the Go scaffold, YAML configuration loading and validation, and a minimal API entry point.

Add development and production Compose files, a multi-stage Docker image, configuration template, and Make targets. Remove the directory scaffolding script.

Dockerfile

@@ -0,0 +1,26 @@
+FROM golang:1.27-alpine AS build
+
+WORKDIR /src
+
+COPY go.mod go.sum ./
+RUN go mod download
+
+COPY . .
+RUN CGO_ENABLED=0 GOOS=linux go build \
+    -trimpath \
+    -ldflags="-s -w" \
+    -o /out/robot-market-api \
+    ./cmd/api
+
+FROM alpine:3.22 AS production
+
+RUN apk add --no-cache ca-certificates \
+    && addgroup -S app \
+    && adduser -S -G app app
+
+COPY --from=build /out/robot-market-api /usr/local/bin/robot-market-api
+
+USER app
+EXPOSE 8080
+
+ENTRYPOINT ["/usr/local/bin/robot-market-api"]