📝 docs: clarify Dockerfile.prod usage and add warnings about latest tag

Dockerfile.prod

@@ -1,7 +1,9 @@
 # DanceLessonsCoach Production Docker Image
-# Minimal image using pre-built binary from CI cache
+# ⚠️ DEVELOPMENT ONLY - This file uses 'latest' tag for local testing
+# ⚠️ CI/CD generates the correct Dockerfile.prod with proper dependency hash
+# ⚠️ For production use, see the CI/CD workflow which generates the correct file
 
-# Use the build cache image as base
+# Use the build cache image as base (latest for local dev only)
 FROM gitea.arcodange.lab/arcodange/dance-lessons-coach-build-cache:latest AS builder
 
 # Final minimal image

scripts/test-local-ci-cd.sh

@@ -96,7 +96,9 @@ if [ "$HAS_DOCKER" = true ]; then
     echo ""
     
     echo "2. Build production image using Dockerfile.prod:"
+    echo "   # Note: Local Dockerfile.prod uses 'latest' tag for testing"
     echo "   docker build -t dance-lessons-coach-prod:$CURRENT_VERSION -f Dockerfile.prod ."
+    echo "   # For CI/CD, the workflow generates correct Dockerfile.prod with dependency hash"
     echo ""
     
     echo "3. Compare image sizes:"
@@ -272,4 +274,6 @@ echo "🎯 When ready for production:"
 echo "  Push to main branch to trigger full CI/CD pipeline"
 echo "  Docker image will be built and pushed to Gitea Container Registry"
 echo ""
-echo "💡 Local testing complete! Your changes are ready for CI/CD."
+echo "💡 Local testing complete! Your changes are ready for CI/CD."
+# ⚠️  IMPORTANT: Local Dockerfile.prod uses 'latest' tag for testing only
+# ✅ CI/CD workflow generates correct Dockerfile.prod with dependency hash