fix: a credential or host-key prompt takes Enter and Escape from the modals underneath

Every modal read Enter/Escape globally, so a prompt that popped up over a
dialog, the palette, Quick Connect or an SFTP dialog could be answered
and the modal underneath confirmed or dismissed by the same key press.
All modals except the prompts now read those keys through
chrome::modal_key, which yields while a prompt is on screen.

rust/app/src/app.rs

@@ -931,7 +931,7 @@ impl eframe::App for App {
         if self.palette.is_none() && self.dialog.is_none() && self.prompts.is_empty() {
             self.shortcuts(&ctx);
         }
-        if ctx.input(|i| i.key_pressed(Key::Escape)) && ctx.input(|i| i.viewport().fullscreen.unwrap_or(false)) && self.palette.is_none() {
+        if crate::chrome::modal_key(&ctx, Key::Escape) && ctx.input(|i| i.viewport().fullscreen.unwrap_or(false)) && self.palette.is_none() {
             ctx.send_viewport_cmd(egui::ViewportCommand::Fullscreen(false));
         }
         self.file_drops(&ctx);
@@ -979,6 +979,8 @@ impl eframe::App for App {
         egui::CentralPanel::default().frame(egui::Frame::NONE.fill(t.dock)).show(ui, |ui| tabs::workspace(self, ui));
 
         // Floating windows and modals.
+        let prompt_open = !self.prompts.is_empty();
+        ctx.data_mut(|d| d.insert_temp(egui::Id::new("nexus-prompt-open"), prompt_open));
         self.quick.ui(&ctx, &mut self.s);
         self.settings.ui(&ctx, &mut self.s);
         self.keys.ui(&ctx, &mut self.s);