Enhance Dockerfile to create a writable workspace under /srv/LeafWeb and update piscal_manager.sh to check for write permissions on working directories.

Dockerfile

@@ -67,6 +67,13 @@ RUN set -xe \
 RUN set -xe \
 	&& mkdir /run/sshd
 
+# Ensure the job/workspace base under /srv is writable.
+# The client uses `/srv/${PiscalDirectoryName}/input` and `PiscalDirectoryName`
+# can itself be prefixed with `LeafWeb/...`.
+RUN set -xe \
+	&& mkdir -p /srv/LeafWeb \
+	&& chown -R ${SSH_USERNAME}:${SSH_GROUP} /srv/LeafWeb
+
 # Create storage directory structure with proper ownership
 RUN set -xe \
 	&& mkdir -p ${STORAGE_PATH}/input \