fix: Correct working directory and source code paths in Dockerfile

Dockerfile

@@ -5,7 +5,7 @@ FROM golang:1.24.4-alpine AS builder
 RUN apk add --no-cache git
 
 # Set working directory
-WORKDIR /app
+WORKDIR /build
 
 # Copy go mod files from root directory
 COPY go.mod go.sum ./
@@ -13,11 +13,11 @@ COPY go.mod go.sum ./
 # Download dependencies
 RUN go mod download
 
-# Copy source code from app directory
-COPY app/ .
+# Copy the entire app directory to maintain the module structure
+COPY app/ ./app/
 
-# Build the application
-RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o authenticator authenticator.go
+# Build the application from the app directory
+RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o authenticator ./app/authenticator.go
 
 # Production stage
 FROM alpine:latest
@@ -28,10 +28,10 @@ RUN apk --no-cache add ca-certificates
 WORKDIR /root/
 
 # Copy binary from builder
-COPY --from=builder /app/authenticator .
+COPY --from=builder /build/authenticator .
 
 # Copy config file
-COPY --from=builder /app/etc/authenticator.yaml ./etc/
+COPY app/etc/authenticator.yaml ./etc/
 
 # Expose port
 EXPOSE 8888