feat: ledger-gui — a read-only, live desktop view of the books

egui/wgpu app for owners and their accountant: Overview, Cash, Profit,
Transactions (with rendered receipts and journal history), Reports
(statements with interval columns, comparisons, drill-down), Accounts,
Documents, Company, Journal; Ctrl+K palette; back/forward; light/dark.
Follows the journal live (~30 ms from write to screen). --demo opens a
deterministic demo company, also used for screenshot tests.

Engine: ledger-store Snapshot (read-only, incremental, tolerant of a
half-written tail); ledger-core analysis (intervals, balance series,
P&L by interval, cash flows); ledger-config extracted from ledger-mcp
with the full company profile and cash_accounts.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MtYEaR6M6Ybdhm6X98BWNu

crates/ledger-gui/src/pages/mod.rs

@@ -0,0 +1,156 @@
+//! One module per screen.
+
+pub mod accounts;
+pub mod cash;
+pub mod company;
+pub mod documents;
+pub mod entry;
+pub mod journal;
+pub mod overview;
+pub mod profit;
+pub mod reports;
+pub mod transactions;
+
+use crate::app::Shell;
+use crate::books::Books;
+use crate::nav::Route;
+use egui::{Margin, Ui};
+
+/// Standard page body: scrollable, padded.
+pub fn page(ui: &mut Ui, id: &str, add: impl FnOnce(&mut Ui)) {
+    egui::ScrollArea::vertical()
+        .id_salt(id)
+        .auto_shrink(false)
+        .show(ui, |ui| {
+            egui::Frame::new()
+                .inner_margin(Margin {
+                    left: 32,
+                    right: 32,
+                    top: 24,
+                    bottom: 40,
+                })
+                .show(ui, |ui| {
+                    ui.set_width(ui.available_width());
+                    add(ui)
+                });
+        });
+}
+
+pub fn show(ui: &mut Ui, b: &Books, route: &Route, shell: &mut Shell<'_>) {
+    match route {
+        Route::Overview => overview::show(ui, b, shell),
+        Route::Cash => cash::show(ui, b, shell),
+        Route::Profit => profit::show(ui, b, shell),
+        Route::Transactions => transactions::show(ui, b, None, shell),
+        Route::Entry(id) => transactions::show(ui, b, Some(*id), shell),
+        Route::Reports(kind) => reports::show(ui, b, *kind, shell),
+        Route::Accounts => accounts::show_chart(ui, b, shell),
+        Route::Account(id) => accounts::show_account(ui, b, *id, shell),
+        Route::Documents => documents::show(ui, b, None, shell),
+        Route::Document(id) => documents::show(ui, b, Some(*id), shell),
+        Route::Company => company::show(ui, b, shell),
+        Route::Journal => journal::show(ui, b, None, shell),
+        Route::JournalEvent(seq) => journal::show(ui, b, Some(*seq), shell),
+    }
+}
+
+/// Columns sized by `weights` when the page is at least `min_width`
+/// wide; stacked otherwise. `add(i, ui)` fills column `i`.
+pub fn columns(ui: &mut Ui, min_width: f32, weights: &[f32], mut add: impl FnMut(usize, &mut Ui)) {
+    let gap = 16.0;
+    if ui.available_width() < min_width {
+        for i in 0..weights.len() {
+            add(i, ui);
+            ui.add_space(gap);
+        }
+        return;
+    }
+    let total: f32 = weights.iter().sum();
+    let avail = ui.available_width() - gap * (weights.len() as f32 - 1.0);
+    let top = ui.cursor().min;
+    let mut x = top.x;
+    let mut bottom = top.y;
+    for (i, w) in weights.iter().enumerate() {
+        let width = avail * w / total;
+        let rect =
+            egui::Rect::from_min_size(egui::pos2(x, top.y), egui::vec2(width, f32::INFINITY));
+        let mut child = ui.new_child(
+            egui::UiBuilder::new()
+                .max_rect(rect)
+                .layout(egui::Layout::top_down(egui::Align::Min)),
+        );
+        child.set_width(width);
+        add(i, &mut child);
+        bottom = bottom.max(child.min_rect().bottom());
+        x += width + gap;
+    }
+    let used = egui::Rect::from_min_max(top, egui::pos2(top.x + ui.available_width(), bottom));
+    ui.advance_cursor_after_rect(used);
+    ui.add_space(gap);
+}
+
+/// A list on the left and a detail pane on the right, split by a
+/// draggable divider. The split is remembered per `id`.
+pub fn split<T: ?Sized>(
+    ui: &mut Ui,
+    id: &str,
+    default_detail: f32,
+    state: &mut T,
+    left: impl FnOnce(&mut Ui, &mut T),
+    right: impl FnOnce(&mut Ui, &mut T),
+) {
+    let p = crate::theme::pal(ui.ctx());
+    let rect = ui.available_rect_before_wrap();
+    let key = egui::Id::new(("split", id));
+    let mut detail_w: f32 = ui
+        .ctx()
+        .data_mut(|d| d.get_persisted(key))
+        .unwrap_or(default_detail);
+    detail_w = detail_w.clamp(360.0, (rect.width() - 380.0).max(360.0));
+    let divider_x = rect.right() - detail_w;
+    let left_rect = egui::Rect::from_min_max(rect.min, egui::pos2(divider_x, rect.bottom()));
+    let right_rect = egui::Rect::from_min_max(egui::pos2(divider_x + 1.0, rect.top()), rect.max);
+    ui.painter().rect_filled(right_rect, 0.0, p.surface);
+    ui.painter().line_segment(
+        [
+            egui::pos2(divider_x, rect.top()),
+            egui::pos2(divider_x, rect.bottom()),
+        ],
+        egui::Stroke::new(1.0, p.border),
+    );
+    let mut l = ui.new_child(
+        egui::UiBuilder::new()
+            .max_rect(left_rect)
+            .layout(egui::Layout::top_down(egui::Align::Min)),
+    );
+    l.set_clip_rect(left_rect);
+    left(&mut l, state);
+    let inner = right_rect.shrink2(egui::vec2(24.0, 20.0));
+    let mut r = ui.new_child(
+        egui::UiBuilder::new()
+            .max_rect(inner)
+            .layout(egui::Layout::top_down(egui::Align::Min)),
+    );
+    r.set_clip_rect(right_rect);
+    right(&mut r, state);
+    let handle = egui::Rect::from_center_size(
+        egui::pos2(divider_x, rect.center().y),
+        egui::vec2(8.0, rect.height()),
+    );
+    let resp = ui.interact(handle, key.with("handle"), egui::Sense::drag());
+    if resp.hovered() || resp.dragged() {
+        ui.ctx().set_cursor_icon(egui::CursorIcon::ResizeHorizontal);
+        ui.painter().line_segment(
+            [
+                egui::pos2(divider_x, rect.top()),
+                egui::pos2(divider_x, rect.bottom()),
+            ],
+            egui::Stroke::new(2.0, p.accent),
+        );
+    }
+    if resp.dragged() {
+        detail_w -= resp.drag_delta().x;
+        ui.ctx().data_mut(|d| d.insert_persisted(key, detail_w));
+    }
+    ui.allocate_rect(rect, egui::Sense::hover());
+}