M5: the group parity note says what deleting does across readers

Deleting any member deletes its group on the page, as ISO 32000-2
§12.5.6.2 has it and PDF-XChange and Foxit do; a subordinate whose primary
is on another page is a comment of its own and stays. The note's Missing
list no longer says such a subordinate can't be selected, and the
cross-page test is its evidence.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Pq7HyCfwzyRXj4VfQAVVdv

parity/acrobat-features.toml

@@ -3595,8 +3595,8 @@ milestone = "M3"
 status = "shipped"
 commands = ["comment.list"]
 tools = ["comment_list"]
-evidence = ["crates/ui-egui/tests/it/ui.rs::opening_a_pdf_shows_comments_and_bookmarks", "crates/ui-egui/tests/it/comments.rs::the_panel_posts_comments_and_replies", "crates/ui-egui/tests/it/comments.rs::page_groups_collapse_and_expand", "crates/ui-egui/tests/it/comments.rs::replies_follow_irt_references_when_names_repeat_on_every_page", "crates/engine/src/tests.rs::replies_thread_by_reference_when_names_repeat_across_pages", "crates/automation/tests/it/automation.rs::replies_thread_by_reference_when_ids_repeat_across_pages", "crates/ui-egui/tests/it/comments.rs::a_group_is_one_comment_in_the_panel_and_on_the_page", "crates/automation/tests/it/automation.rs::a_group_lists_as_its_primary", "crates/automation/tests/it/automation.rs::looping_groups_end_and_chained_groups_reach_their_primary", "crates/render/src/inspect/tests.rs::group_primaries_follow_irt_to_the_first_non_subordinate"]
-notes = "cards grouped by page with replies (threaded by the `/IRT` reference, so files whose `/NM` repeats per page, as PyMuPDF writes them, thread correctly; the header counts comments without replies, as Acrobat does), status badges, selection, reply box and an Add a comment box; page groups fold and unfold from their chevron or with Collapse/Expand all pages in the panel's \"…\" menu (a comment selected on a folded page opens its group). Groups by author, type or colour don't fold yet. Annotation groups (`/RT /Group`, ISO 32000-2 §12.5.6.2) list as one comment with the primary's author, text and colour (the subordinate's own are ignored), a reply to a subordinate joins the primary's thread, `comment_list` names the members in `group`, clicking a subordinate on the page selects the group and deleting any member deletes the group (one undo step). Missing: moving or restyling a member does not move or restyle the group, a subordinate has no hover tooltip, and a subordinate whose primary is on another page is selected on neither"
+evidence = ["crates/ui-egui/tests/it/ui.rs::opening_a_pdf_shows_comments_and_bookmarks", "crates/ui-egui/tests/it/comments.rs::the_panel_posts_comments_and_replies", "crates/ui-egui/tests/it/comments.rs::page_groups_collapse_and_expand", "crates/ui-egui/tests/it/comments.rs::replies_follow_irt_references_when_names_repeat_on_every_page", "crates/engine/src/tests.rs::replies_thread_by_reference_when_names_repeat_across_pages", "crates/automation/tests/it/automation.rs::replies_thread_by_reference_when_ids_repeat_across_pages", "crates/ui-egui/tests/it/comments.rs::a_group_is_one_comment_in_the_panel_and_on_the_page", "crates/automation/tests/it/automation.rs::a_group_lists_as_its_primary", "crates/automation/tests/it/automation.rs::a_group_member_on_another_page_is_a_comment_of_its_own", "crates/automation/tests/it/automation.rs::looping_groups_end_and_chained_groups_reach_their_primary", "crates/render/src/inspect/tests.rs::group_primaries_follow_irt_to_the_first_non_subordinate"]
+notes = "cards grouped by page with replies (threaded by the `/IRT` reference, so files whose `/NM` repeats per page, as PyMuPDF writes them, thread correctly; the header counts comments without replies, as Acrobat does), status badges, selection, reply box and an Add a comment box; page groups fold and unfold from their chevron or with Collapse/Expand all pages in the panel's \"…\" menu (a comment selected on a folded page opens its group). Groups by author, type or colour don't fold yet. Annotation groups (`/RT /Group`, ISO 32000-2 §12.5.6.2) list as one comment with the primary's author, text and colour (the subordinate's own are ignored), a reply to a subordinate joins the primary's thread, `comment_list` names the members in `group`, clicking a subordinate on the page selects the group, and deleting any member deletes its group on the page (one undo step), as ISO 32000-2 §12.5.6.2 has it and PDF-XChange and Foxit do (Acrobat desktop deletes only the member clicked). A group is one page's: a subordinate whose primary is on another page is a comment of its own, listed, selected and deleted on its own, and it stays when the primary is deleted, as Acrobat (desktop and iPad) and PDF-XChange read it. Missing: moving or restyling a member does not move or restyle the group, and a subordinate has no hover tooltip"
 
 [[feature]]
 id = "comment.appearance-generation"