🗂️ refactor: organize Dockerfiles into docker/ directory and update all references

docker/Dockerfile

@@ -0,0 +1,57 @@
+# DanceLessonsCoach Docker Image
+# Multi-stage build for production deployment
+
+# Stage 1: Build binary
+FROM golang:1.26.1-alpine AS builder
+
+WORKDIR /app
+
+# Copy go mod files
+COPY go.mod go.sum ./
+RUN go mod download
+
+# Copy source code
+COPY . ./
+
+# Install swag and generate Swagger docs only if they don't exist
+RUN if [ ! -f pkg/server/docs/swagger.json ]; then \
+    echo "📝 Generating Swagger documentation..." && \
+    go install github.com/swaggo/swag/cmd/swag@latest && \
+    cd pkg/server && go generate && \
+    echo "✅ Swagger documentation generated"; \
+    else \
+    echo "✅ Swagger documentation already exists, skipping swag installation and generation"; \
+    fi
+
+# Build binary
+RUN CGO_ENABLED=0 GOOS=linux go build -o /dance-lessons-coach ./cmd/server
+
+# Stage 2: Final image
+FROM alpine:3.18
+
+WORKDIR /app
+
+# Install dependencies
+RUN apk add --no-cache ca-certificates tzdata
+
+# Copy binary from builder
+COPY --from=builder /dance-lessons-coach /app/dance-lessons-coach
+
+# Copy configuration
+COPY config.yaml /app/config.yaml
+
+# Set permissions
+RUN chmod +x /app/dance-lessons-coach
+
+# Set timezone
+ENV TZ=UTC
+
+# Expose port
+EXPOSE 8080
+
+# Health check
+HEALTHCHECK --interval=30s --timeout=3s \
+    CMD wget -q --spider http://localhost:8080/api/health || exit 1
+
+# Entry point
+ENTRYPOINT ["/app/dance-lessons-coach"]