🗑️ chore: remove unused files and update ADR with cleanup information

adr/0020-docker-build-strategy.md

@@ -446,13 +446,35 @@ echo "Hash: $DEPS_HASH"
 docker run --rm -i hadolint/hadolint < Dockerfile.prod
 ```
 
+## Cleanup and Organization
+
+### Files Removed
+
+1. **docker-compose.cicd-test.yml**: Unused Docker Compose file
+2. **scripts/cicd/**: Old CI/CD test scripts (replaced by main test scripts)
+
+### Files Organized
+
+All Dockerfiles moved to `docker/` directory:
+- `docker/Dockerfile` - Development
+- `docker/Dockerfile.build` - Build cache
+- `docker/Dockerfile.prod` - Production (dev only)
+- `docker/Dockerfile.prod.template` - Template
+
+### Utility Scripts
+
+- `scripts/calculate-deps-hash.sh` - Consistent hash calculation
+- `scripts/test-local-ci-cd.sh` - Main local testing
+- `scripts/test-build-cache-environment.sh` - Build cache testing
+
 ## Expected Outcomes
 
-1. **Successful workflow execution**: Workflow 419 completes without errors
+1. **Successful workflow execution**: Workflow completes without errors
 2. **Cache image created**: Build cache image pushed to registry
-3. **Production image built**: Final Docker image built using `Dockerfile.prod`
+3. **Production image built**: Final Docker image built using generated `docker/Dockerfile.prod`
 4. **Faster CI execution**: Reduced build times compared to previous approach
 5. **No certificate errors**: No TLS certificate verification failures
+6. **Clean organization**: No clutter in root directory
 
 ## References