M3: going Home puts the expanded All tools away with no document open

With no document open the expanded view covers Home itself, so the control
option `home` changed no tab and the view stayed up (CodeRabbit's remaining
merge-risk note on 8a8bb92d). The option now puts the view away itself.
`going_home_with_no_document_puts_the_expanded_all_tools_away` was seen to
fail with the fix reverted.

Also doc comments on the view's `show` and `tile` and the sidebar's
`all_tools`, for CodeRabbit's docstring-coverage check.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

crates/ui-egui/src/all_tools_ui.rs

@@ -36,6 +36,8 @@ fn matches(query: &str, group: &ToolGroup) -> Option<Vec<&'static str>> {
     (!items.is_empty()).then_some(items)
 }
 
+/// Draw the view over the workspace: the title with Collapse, the search field, and each
+/// category's tiles that match the search. Choosing a tile opens that tool's panel.
 pub fn show(app: &mut PdfCraftApp, ui: &mut egui::Ui) {
     let t = Tokens::get(ui.ctx());
     // A dialog or prompt over the view owns Escape.
@@ -103,6 +105,9 @@ pub fn show(app: &mut PdfCraftApp, ui: &mut egui::Ui) {
     }
 }
 
+/// One tool's tile: its icon and name, then the `items` the search found it by or, when there are
+/// none, its availability (a planned tool is greyed out with its milestone). A name or note cut
+/// short shows in full on hover.
 fn tile(ui: &mut egui::Ui, t: &Tokens, g: &ToolGroup, items: &[&'static str]) -> egui::Response {
     let (rect, resp) = ui.allocate_exact_size(TILE, Sense::click());
     resp.widget_info(|| egui::WidgetInfo::labeled(egui::WidgetType::Button, true, tl!(g.label)));

crates/ui-egui/src/lib.rs

@@ -2712,7 +2712,12 @@ impl PdfCraftApp {
                 self.select_tool(g.id);
             }
             ("left", _) => self.left_open = value != "closed",
-            ("home", _) => self.active = None,
+            ("home", _) => {
+                self.active = None;
+                // With no document open the expanded All tools view covers Home itself, so no
+                // other tab comes forward to put it away.
+                self.all_tools_full = false;
+            }
             ("dialog", _) => {
                 self.dialog = match value {
                     "properties" => Some(Dialog::Properties(PropsTab::Description)),

crates/ui-egui/src/panels.rs

@@ -62,6 +62,8 @@ pub(crate) fn panel_header(ui: &mut egui::Ui, t: &Tokens, title: &str, lead: Opt
     (go_back, close)
 }
 
+/// The All tools sidebar: Expand (the full view) and Close, then the tool list, the first few
+/// tools until View more shows them all.
 fn all_tools(app: &mut PdfCraftApp, ui: &mut egui::Ui, t: &Tokens) {
     // Labels distinct from the Combine grid's Expand and Collapse, which can show beside them.
     let (expand, close) = panel_header(ui, t, "All tools", Some(("maximize-2", tl!("Expand all tools"))));

crates/ui-egui/tests/ui.rs

@@ -240,6 +240,16 @@ fn another_tab_coming_forward_puts_the_expanded_all_tools_away() {
     assert!(!h.state().all_tools_full, "one.pdf shows, not the catalogue over it");
 }
 
+#[test]
+fn going_home_with_no_document_puts_the_expanded_all_tools_away() {
+    // Home is already the tab in front, so only the option itself can put the view away.
+    let mut h = harness(|app| app.set_option("tools", "full").unwrap());
+    h.state_mut().set_option("home", "").unwrap();
+    h.run_steps(3);
+    assert!(!h.state().all_tools_full);
+    h.get_by_label_contains("Welcome to PdfCraft");
+}
+
 #[test]
 fn expanding_all_tools_from_read_mode_restores_the_right_panel() {
     use pdfcraft_ui_egui::{Mode, RightPanel};