P2 slice 6: the viewer

`wanderbooks gui [BOOK]` finds the data root, reads settings from the
journal, the vault of the book, presence through ops/, Save a copy /
Open on every document, Save the W-9, the Export menu, and colour
schemes. One builder for the CPA package and the 1099 worksheet
(ledger-package), shared by the server and the viewer.

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

crates/ledger-gui/src/attention.rs

@@ -676,7 +676,6 @@ mod tests {
         ledger_store::Store::create(&data_dir, ledger_core::Currency::USD).unwrap();
         crate::data::load_once(&crate::data::Source {
             data_dir,
-            books_toml: None,
             today: Some(today),
         })
         .unwrap()