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-store/tests/settings.rs

@@ -609,6 +609,7 @@ fn decisions_and_open_items() {
         evidence_attachment: evidence,
         supersedes,
         citation: Some("Treas. Reg. 1.263(a)-1(f)".into()),
+        projects: vec![],
     };
     assert_eq!(s.record_decision(&decision(None, Some(doc))).unwrap(), 1);
     assert_eq!(s.record_decision(&decision(Some(1), None)).unwrap(), 2);
@@ -756,6 +757,7 @@ fn run_op(s: &mut Store, op: &Op) {
                 evidence_attachment: None,
                 supersedes: *sup,
                 citation: None,
+                projects: vec![],
             })
             .map(|_| ()),
         Op::Raise => s
@@ -978,6 +980,7 @@ fn write_p1_fixture() {
         evidence_attachment: Some(doc),
         supersedes: None,
         citation: Some("Treas. Reg. 1.263(a)-1(f)".into()),
+        projects: vec![],
     })
     .unwrap();
     s.record_decision(&NewDecision {
@@ -988,6 +991,7 @@ fn write_p1_fixture() {
         evidence_attachment: None,
         supersedes: Some(1),
         citation: None,
+        projects: vec![],
     })
     .unwrap();
     s.raise_open_item(&NewOpenItem {