🤖 ci: optimize CI/CD with Docker cache and remove Buildx

Dockerfile.prod

@@ -0,0 +1,35 @@
+# DanceLessonsCoach Production Docker Image
+# Minimal image using pre-built binary from CI cache
+
+# Use the build cache image as base
+FROM gitea.arcodange.lab/arcodange/dance-lessons-coach-build-cache:latest AS builder
+
+# Final minimal image
+FROM alpine:3.18
+
+WORKDIR /app
+
+# Install minimal dependencies
+RUN apk add --no-cache ca-certificates tzdata
+
+# Copy binary from builder
+COPY --from=builder /workspace/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"]