fix(drafts): index a saved draft so it appears without a sync

Autosave writes the draft to the Maildir drafts folder and stops, while
the Drafts view is a notmuch path: query, so a freshly saved draft was
invisible until notmuch new ran. saveDraftNow() now emits draftSaved, and
MainWindow connects it to a new NotmuchWorker::indexDraftFile() that
indexes the one file the way moveMessages() does, with the previous
revision removed so a rewrite leaves no ghost.

The send path unlinks a draft that was indexed while being composed, so
draftRemoved -> removeIndexedFile() drops its entry too.

Measured: notmuch_database_index_file assigns NO tags (unlike notmuch
new, which adds draft inbox unread), so no tag-stripping is needed and the
draft cannot leak into a tag:inbox view.

Item 158.

1 files changed, 11 insertions, 0 deletions

diff --git a/src/mainwindow.cpp b/src/mainwindow.cpp
index 99eb2a3..af3b817 100644
--- a/src/mainwindow.cpp
+++ b/src/mainwindow.cpp
@@ -1138,6 +1138,17 @@ void MainWindow::openComposer(const ComposeContext &context)
                 });
             });
 
+    // A saved draft is indexed immediately (item 158): the Drafts view is a
+    // path query, and without this the draft is invisible until the next sync.
+    // The worker lives on another thread, so this is a queued connection and
+    // notmuch stays on its own thread.
+    connect(composer, &ComposeWindow::draftSaved, m_worker,
+            &NotmuchWorker::indexDraftFile);
+
+    // A draft unlinked on send must leave no ghost entry behind.
+    connect(composer, &ComposeWindow::draftRemoved, m_worker,
+            &NotmuchWorker::removeIndexedFile);
+
     composer->show();
 }