feat: add Docker build

Dockerfile

@@ -0,0 +1,42 @@
+# Build stage
+FROM golang:1.22-alpine AS builder
+
+WORKDIR /app
+
+# Install build dependencies for CGO
+RUN apk add --no-cache gcc musl-dev sqlite-dev
+
+# Copy go mod files
+COPY go.mod go.sum ./
+RUN go mod download
+
+# Copy source code
+COPY . .
+
+# Build the application
+# Note: CGO_ENABLED=1 is required for sqlite3
+RUN CGO_ENABLED=1 GOOS=linux go build -a -installsuffix cgo -o spore-registry ./main.go
+
+# Runtime stage
+FROM alpine:latest
+
+# Install ca-certificates, sqlite runtime, and wget for health checks
+RUN apk --no-cache add ca-certificates sqlite wget
+
+WORKDIR /root/
+
+# Copy the binary from builder
+COPY --from=builder /app/spore-registry .
+
+# Create registry directory
+RUN mkdir -p /data/registry
+
+# Expose port
+EXPOSE 8080
+
+# Set environment variable for registry path
+ENV REGISTRY_PATH=/data/registry
+
+# Run the application
+CMD ["./spore-registry"]
+