Add Quick Connect: open a session without saving a profile first

File > Quick Connect... and a matching Profiles-tab button open
ProfileDialog in a new quick-connect mode (Name/Tags/Folder hidden,
Name validation skipped) and hand the resulting in-memory profile
straight to a session tab -- nothing is written to the profile
database. The tab title is derived from host/username/protocol for
display only. A Quick Connect tab's context menu gets a "Save as
Profile..." action, shown only on tabs that were never saved, that
opens the normal profile dialog pre-filled to persist it afterward.

Bump version to v2026.9.28.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/session_tab.h

@@ -69,6 +69,14 @@ public:
     void setVncScaleToFit(bool scaleToFit);
     bool vncScaleToFit() const;
     bool awaitingUserInput() const;
+    // True if this tab's profile was never saved to the repository (i.e.
+    // it came from Quick Connect, issue #23, rather than a saved profile).
+    // ProfileDialog::profile() always returns id <= 0 for an unsaved
+    // profile, and Quick Connect is the only path that hands such a
+    // profile to SessionWindow::addSessionTab() -- every other path looks
+    // the profile up from the repository first, which returns id > 0.
+    bool isQuickConnect() const;
+    Profile profileForSaving() const;
 
 signals:
     void tabTitleChanged(const QString& title);