Cloud session file staging gains in-place writes, retry sorting and a 'session full' breaker

What

A cloud session is a Claude Code session that runs on a remote machine rather than on your own computer. Files are copied into it through a step called staging, and kept in step through a synced-file push. Both changed:

• The stage_file handler now passes on the id of the request it is answering, and a new check sorts failures into permanent ones and temporary ones worth retrying. Before, any failed response counted as permanent.
• The file list call to /worker/files can now carry a query parameter. Before, it had none.
• The handler accepts in_place requests, which write the file where it belongs instead of writing a temporary file and renaming it. Their id must match the pattern stage-file-inplace-req_.... For these requests, a read-only folder is no longer quietly treated as nothing to do.
• The synced-file push (ccr_synced_file_push) gains a 'session full' breaker. Once a failure shows the session's storage is full, it is recorded as full, and later pushes are rejected without being sent. A probe push at intervals checks whether there is room again, then clears the full state or schedules another check. A file that is not found when fetched again triggers an immediate re-check.

Why

Once a cloud session's storage is full, it no longer keeps retrying every file push, and temporary staging failures can be told apart from permanent ones. These changes only touch remote sessions and are driven by the server, so nothing changes for sessions on your own computer.