Engine: the setup checklist (Session::progress), returned by model.check

The analysis stages in order (geometry, seeds & partitions, mesh, material, section, sets,
boundary conditions, loads, step, solve, results), each done, next, todo, blocked or optional,
with the command that does it. Built on the command requirements; Solve also reads the model
check's first error.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo

crates/engine/src/lib.rs

@@ -18,6 +18,7 @@ pub mod cmd;
 
 pub use cmd::analytic_surfaces;
 pub mod history;
+pub mod progress;
 pub mod requirement;
 pub mod results;
 pub mod sample;