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-mcp/src/handbook.rs

@@ -71,6 +71,7 @@ pub const SECTIONS: &[(&str, &str)] = &[
         "revenue-and-payouts",
         include_str!("../handbook/revenue-and-payouts.md"),
     ),
+    ("projects", include_str!("../handbook/projects.md")),
     (
         "parties-and-tins",
         include_str!("../handbook/parties-and-tins.md"),