feat(kernel): Add working directory log to build script

Log the current working directory in `build-in-docker.sh` to improve the
debugging process during kernel module compilation. This update helps
track the build context path passed to the Docker container.

kernel/build-in-docker.sh

@@ -40,6 +40,7 @@ docker build --platform linux/arm64 \
 
 # 3. Compile; mount this dir so the .ko lands on the host, owned by the caller.
 echo "==> compiling module"
+echo "working directory: $PWD"
 docker run --rm --platform linux/arm64 \
 	-u "$(id -u):$(id -g)" -e HOME=/tmp \
 	-v "$PWD:/build" "$IMAGE" "$@"