Write a live snapshot of the current solution to snapshot_file.
The file is overwritten on each call. A header comment records the
current iteration and time; subsequent rows are (x, ρ, u, p) in
'(4ES20.12)' format. Open/write failures are logged as warnings
rather than fatal errors so that a snapshot glitch does not abort
the run.
This file path is retained for compatibility with legacy file-watching
tooling; new integrations should prefer the polling session/API surface.
| Type | Intent | Optional | Attributes | Name | ||
|---|---|---|---|---|---|---|
| class(solver_run_context_t), | intent(inout) | :: | ctx |
Solver context (gather_buf is updated; all other fields are read-only). |