Execution environment for a workspace on shared storage (NFS, CephFS, a read-write-many volume).

Reads, listing and commands are the same as SuperPi.Env.Local. Writes and edits also take a PostgreSQL advisory lock for the path, so two nodes cannot change the same file at once. The SuperPi.Env.FileLock that Local uses only serializes writers on one node.

With SQLite (one node) there is no other node, so the local lock is enough and no advisory lock is taken.