Fix connect-time username prompt never reaching SSH/RDP authentication

The username entered at the connect-time prompt (added for issue #21)
was updating SessionTab's own in-memory Profile copy, but
SshSessionBackend/RdpSessionBackend are constructed with -- and only
ever read from -- their own separate Profile copy on a worker thread,
which never saw that edit. Authentication was still built from the
original (blank) username regardless of what was typed into the
prompt.

SessionConnectOptions gains a username field, populated by SessionTab
on every connect attempt and threaded through the same way password
already is; both backends now prefer options.username over
profile().username. Covered by a new SSH regression test using an
exact-match fixture host that only succeeds for a specific
user@host target.

Bump version to v2026.9.16.5.

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

src/rdp_session_backend.cpp

@@ -1640,7 +1640,13 @@ void RdpSessionBackend::workerMain()
     const Profile& p = profile();
 
     const QString host = p.host.trimmed();
-    QString username = p.username.trimmed();
+    // m_activeOptions.username carries a value prompted for at connect time
+    // (see SessionTab::requestConnectOptions()) when the saved profile's
+    // own username was blank; profile().username never sees that edit
+    // since this backend's Profile copy was captured at construction time.
+    QString username = m_activeOptions.username.trimmed().isEmpty()
+        ? p.username.trimmed()
+        : m_activeOptions.username.trimmed();
     QString domain = p.domain.trimmed();
     if (domain.isEmpty()) {
         const int domainSeparator = username.indexOf(QLatin1Char('\\'));

src/session_backend.h

@@ -12,6 +12,12 @@
 class SessionConnectOptions
 {
 public:
+    // Only set when the profile's own username was blank and SessionTab
+    // prompted for one inline at connect time (see issue #21); empty means
+    // "use the backend's own profile().username" as before. SSH/RDP need
+    // this up front, unlike VNC's Apple auth which discovers the need for
+    // one mid-connection via usernameRequested()/provideUsername() instead.
+    QString username;
     QString password;
     QString privateKeyPath;
     QString knownHostsPolicy;

src/session_tab.cpp

@@ -998,6 +998,10 @@ void SessionTab::requestConnectOptions(
 {
     SessionConnectOptions baseOptions;
     baseOptions.knownHostsPolicy = m_profile.knownHostsPolicy;
+    // The backend's own Profile copy was captured when it was constructed
+    // and never sees later edits to m_profile (e.g. the username prompt
+    // below) -- it has to travel through here instead.
+    baseOptions.username = m_profile.username.trimmed();
 
     const bool isSsh = m_profile.protocol.compare(QStringLiteral("SSH"), Qt::CaseInsensitive) == 0;
     const bool isRdp = m_profile.protocol.compare(QStringLiteral("RDP"), Qt::CaseInsensitive) == 0;

src/ssh_session_backend.cpp

@@ -388,9 +388,16 @@ bool SshSessionBackend::startSshProcess(const SessionConnectOptions& options)
              << QStringLiteral("PasswordAuthentication=no");
     }
 
-    const QString target = p.username.trimmed().isEmpty()
+    // options.username carries a value prompted for at connect time (see
+    // SessionTab::requestConnectOptions()) when the saved profile's own
+    // username was blank; profile().username never sees that edit since
+    // the backend's Profile copy was captured at construction time.
+    const QString username = options.username.trimmed().isEmpty()
+        ? p.username.trimmed()
+        : options.username.trimmed();
+    const QString target = username.isEmpty()
         ? p.host.trimmed()
-        : QStringLiteral("%1@%2").arg(p.username.trimmed(), p.host.trimmed());
+        : QStringLiteral("%1@%2").arg(username, p.host.trimmed());
     args << target;
 
     m_process->setProcessEnvironment(environment);