Projects: classes as entities, and the sidebar fits short windows

A project is a class with facts (description, status, kind, party,
dates, links, notes) in one project.set event behind the format
feature projects. Four tools (books.add_project, update_project,
projects, project); documents and decisions link to projects; B-37:
on-spec costs are expensed as incurred, repayment is revenue, and the
unrecovered cost is never below zero (Kani). Viewer: a Projects list
and a project page with its figures, by month and by account. The
sidebar measures its footer instead of reserving a fixed 172 px.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01T3gXMVt7XJPi6ens1or9Dj

crates/ledger-gui/tests/breadcrumbs.rs

@@ -49,6 +49,7 @@ fn crumbs_link_every_level_but_the_last() {
     let entry = b.entries.first().unwrap().id;
     let mut routes = vec![
         Route::Party(party),
+        Route::Project(b.ledger.list_classes()[0].id),
         Route::Reconciliation(rec.id),
         Route::Entry(entry),
         Route::Reports(ReportKind::ProfitAndLoss),
@@ -112,7 +113,11 @@ fn clicking_a_crumb_goes_there() {
     h.get_all_by_label(&account).next().unwrap().click();
     h.run_steps(3);
     assert_eq!(h.state().route(), &Route::Account(rec.account_id));
-    h.get_by_label("Accounts").click();
+    // The crumb, not the sidebar's link of the same name (left of it).
+    h.get_all_by_label("Accounts")
+        .max_by(|a, b| a.rect().left().total_cmp(&b.rect().left()))
+        .unwrap()
+        .click();
     h.run_steps(3);
     assert_eq!(h.state().route(), &Route::Accounts);
 }