M5: the pop-up windows read the pointer themselves, as Areas over the page (#2137)

main's page_pointer test (#4581) lists the page-module functions that read
egui's pointer state directly; comments::popups hit-tests its own
Foreground windows for the connector line, which is not page input.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0175FWj4xFhMhSH3UpMU8DSC

crates/ui-egui/src/page_pointer.rs

@@ -315,7 +315,7 @@ mod tests {
 
     /// Functions in the page modules that are not page input and read egui's pointer state
     /// themselves: (file, function, why).
-    const NOT_PAGE_INPUT: [(&str, &str, &str); 11] = [
+    const NOT_PAGE_INPUT: [(&str, &str, &str); 12] = [
         ("canvas.rs", "zoom_anchor", "a pinch zooms the whole view, and is read before the pages' widget exists"),
         ("canvas.rs", "drawing_edge_pointer", "scrolls the view at its edges, read before the pages' widget exists"),
         ("canvas.rs", "glide_interrupted", "a press anywhere stops the touchpad's glide"),
@@ -323,6 +323,7 @@ mod tests {
         ("canvas.rs", "page_size_hint", "the page size hint sits in the view's corner, not on a page"),
         ("canvas.rs", "organize_grid", "Organize Pages shows thumbnails, not pages"),
         ("comments.rs", "keys", "keyboard handling after the pages: a drag cancelled with Escape ends once no button is down"),
+        ("comments.rs", "popups", "the comment pop-up windows are Areas of their own over the page"),
         ("forms_ui.rs", "overlay", "the field editor is an Area of its own over the page"),
         ("content_ui.rs", "editor", "the added-text editor is an Area of its own over the page"),
         ("edit_text_ui.rs", "overlay", "the paragraph editor is an Area of its own over the page"),