feat: count a card's messages, not its repliesthread-row-identity

The expander pill read "N replies" while the row stood for the
conversation: a thread of one message and four replies said "4 replies"
over rows that listed all five messages. The user's model is messages, so
it now reads "5 messages". A thread of one still shows nothing: its row is
the message, the pill is the expander, and there is nothing to open.

ReplyCountRole becomes MessageCountRole and CardLayout::Input::replyCount
becomes messageCount, so the names stop lying about what they carry. The
label is now translated under a CardLayout context, with Italian
"messaggio"/"messaggi" shipped; %n's untranslated fallback on this Qt does
not pluralise, so the two forms are separate entries. The card's densest
geometry test needs 460px rather than 400 now that the pill is one
character wider.

1 files changed, 5 insertions, 4 deletions

diff --git a/tests/test_mainwindow.cpp b/tests/test_mainwindow.cpp
index aecefb7..2e7d220 100644
--- a/tests/test_mainwindow.cpp
+++ b/tests/test_mainwindow.cpp
@@ -1396,10 +1396,11 @@ void TestMainWindow::aThreadWithRepliesDrawsAVisibleExpander()
     const QModelIndex first = model->index(0, 0, QModelIndex());
     const QModelIndex second = model->index(1, 0, QModelIndex());
 
-    // Guards: the model agrees about which thread has replies, and only that
-    // one is offered an expander at all.
-    QCOMPARE(model->data(first, ThreadListModel::ReplyCountRole).toInt(), 2);
-    QCOMPARE(model->data(second, ThreadListModel::ReplyCountRole).toInt(), 0);
+    // Guards: the model agrees about which thread has an expander, and only
+    // that one is offered one at all. The count is MESSAGES: the three-message
+    // thread reads 3, the lone message reads 0.
+    QCOMPARE(model->data(first, ThreadListModel::MessageCountRole).toInt(), 3);
+    QCOMPARE(model->data(second, ThreadListModel::MessageCountRole).toInt(), 0);
 
     const QFont font = view->font();
     const int height = CardLayout::heightFor(font);