Preserve editor input context through diagram help

crates/oa-desktop/src/app.rs

@@ -380,6 +380,7 @@ pub enum Message {
     Guide(crate::guide::Event),
     ContextHelp(crate::guide::Topic),
     CloseContextHelp,
+    ContextHelpScroll(crate::guide::ContextScroll),
     Help,
     Traceability(crate::views::traceability::Event),
     ReviewLayerTraces,
@@ -1301,6 +1302,11 @@ impl App {
             iced::time::every(std::time::Duration::from_secs(10)).map(|_| Message::CheckpointTick),
             window::close_requests().map(|id| Message::Request(Pending::Close(id))),
             window::resize_events().map(|(_, size)| Message::WindowResized(size)),
+            if self.context_help {
+                iced::event::listen_with(crate::guide::context_scroll_key)
+            } else {
+                Subscription::none()
+            },
             iced::event::listen_with(|event, _, _| {
                 matches!(
                     event,
@@ -1355,6 +1361,13 @@ impl App {
         ])
     }
     pub fn update(&mut self, message: Message) -> Task<Message> {
+        if let Message::ContextHelpScroll(scroll) = message {
+            return if self.context_help {
+                crate::guide::context_scroll_task(scroll)
+            } else {
+                Task::none()
+            };
+        }
         // Help owns user input before any canvas/reference fast path can act.
         // Passive results may finish; they retain their normal lifetime checks.
         if self.context_help
@@ -2852,6 +2865,7 @@ impl App {
             Message::CloseContextHelp => {
                 self.context_help = false;
             }
+            Message::ContextHelpScroll(_) => {}
             Message::Help => {
                 let topic = match self.page {
                     Page::Diagram => Some(crate::guide::Topic::Nesting),