feat(gui): handle empty sessions in ollie-gui

- getAgents(): filter out 'new' (agent creation file), return empty list
- setActiveSessionId(): skip agent init when no agents exist
- submit/interrupt/kill/streams: guard against empty m_agentId
- prompt input: disable when no agent, show 'No agent' placeholder

gui/main.qml

@@ -193,11 +193,13 @@ ApplicationWindow {
     }
 
     Component.onCompleted: {
+        if (ollie.activeAgentId) {
             var log = ollie.readLogForSession(ollie.activeSessionId, ollie.activeAgentId)
             if (log) {
                 chatModel.appendData(log)
                 chatModel.trimFront(20)
             }
+        }
         scrollTimer.start()
         buildSessionTree()
     }
@@ -206,11 +208,13 @@ ApplicationWindow {
         target: ollie
         function onActiveSessionIdChanged() {
             chatModel.reset()
+            if (ollie.activeAgentId) {
                 var log = ollie.readLogForSession(ollie.activeSessionId, ollie.activeAgentId)
                 if (log) {
                     chatModel.appendData(log)
                     chatModel.trimFront(20)
                 }
+            }
             scrollTimer.start()
             // Expand the active session in the tree
             buildSessionTree()
@@ -886,8 +890,8 @@ property bool blockExpanded: {
                     TextArea {
                         id: promptInput
                         Layout.fillWidth: true
-                        placeholderText: ollie.activeSessionId ? "Message..." : "No session"
+                        placeholderText: !ollie.activeSessionId ? "No session" : !ollie.activeAgentId ? "No agent" : "Message..."
-                        enabled: ollie.activeSessionId !== ""
+                        enabled: ollie.activeSessionId !== "" && ollie.activeAgentId !== ""
                         wrapMode: TextEdit.Wrap
 
                         property string _lastText: ""

gui/ollie9pclient.cpp

@@ -62,13 +62,9 @@ void Ollie9pClient::setActiveSessionId(const QString &id)
     }
 
     // Discover agent ID BEFORE emitting signals
-    QByteArray out = run9p({"ls", "session/" + id + "/agent"});
+    QStringList agents = getAgents(id);
-    QString agents = QString::fromUtf8(out).trimmed();
     if (!agents.isEmpty()) {
-        m_agentId = agents.split('\n').first().trimmed();
+        m_agentId = agents.first();
-    } else {
-        m_agentId = "0";
-    }
 
         // Read initial state immediately (state, not statewait)
         QByteArray stateOut = run9p({"read", agentPath() + "/state"});
@@ -81,6 +77,11 @@ void Ollie9pClient::setActiveSessionId(const QString &id)
 
         startChatStream();
         startStateStream();
+    } else {
+        // Empty session — no agent yet
+        emit activeSessionIdChanged();
+        emit activeStateChanged();
+    }
 }
 
 void Ollie9pClient::refreshSessions()
@@ -126,7 +127,7 @@ QString Ollie9pClient::readLogForSession(const QString &sessionId, const QString
 
 bool Ollie9pClient::submit(const QString &prompt)
 {
-    if (m_activeSessionId.isEmpty() || prompt.trimmed().isEmpty()) return false;
+    if (m_activeSessionId.isEmpty() || m_agentId.isEmpty() || prompt.trimmed().isEmpty()) return false;
     QProcess proc;
     proc.start(ninepBin(), {"-a", serverAddr(), "write", agentPath() + "/prompt"});
     proc.waitForStarted(3000);
@@ -138,7 +139,7 @@ bool Ollie9pClient::submit(const QString &prompt)
 
 bool Ollie9pClient::interrupt()
 {
-    if (m_activeSessionId.isEmpty()) return false;
+    if (m_activeSessionId.isEmpty() || m_agentId.isEmpty()) return false;
     QProcess proc;
     proc.start(ninepBin(), {"-a", serverAddr(), "write", agentPath() + "/ctl"});
     proc.waitForStarted(3000);
@@ -150,7 +151,7 @@ bool Ollie9pClient::interrupt()
 
 bool Ollie9pClient::kill()
 {
-    if (m_activeSessionId.isEmpty()) return false;
+    if (m_activeSessionId.isEmpty() || m_agentId.isEmpty()) return false;
     QProcess proc;
     proc.start(ninepBin(), {"-a", serverAddr(), "write", agentPath() + "/ctl"});
     proc.waitForStarted(3000);
@@ -191,10 +192,15 @@ QStringList Ollie9pClient::getAgents(const QString &sessionId)
     if (sessionId.isEmpty()) return {};
     QByteArray out = run9p({"ls", "session/" + sessionId + "/agent"});
     QString raw = QString::fromUtf8(out).trimmed();
-    if (raw.isEmpty()) return {"0"}; // default fallback
+    if (raw.isEmpty()) return {};
-    QStringList agents = raw.split('\n', Qt::SkipEmptyParts);
+    QStringList all = raw.split('\n', Qt::SkipEmptyParts);
-    for (int i = 0; i < agents.size(); ++i)
+    QStringList agents;
-        agents[i] = agents[i].trimmed();
+    for (const QString &a : all) {
+        QString name = a.trimmed();
+        // "new" is the agent creation file, not an actual agent
+        if (name != "new")
+            agents.append(name);
+    }
     return agents;
 }
 
@@ -425,6 +431,7 @@ void Ollie9pClient::ensureRootDataLoaded()
 void Ollie9pClient::startChatStream()
 {
     if (m_chatProc) return;
+    if (m_activeSessionId.isEmpty() || m_agentId.isEmpty()) return;
     m_chatProc = new QProcess(this);
     connect(m_chatProc, &QProcess::readyReadStandardOutput, this, &Ollie9pClient::onChatReadyRead);
     connect(m_chatProc, QOverload<int, QProcess::ExitStatus>::of(&QProcess::finished),
@@ -437,16 +444,15 @@ void Ollie9pClient::startStateStream()
     if (m_stateProc) return;
 
     // Check if session still exists before starting
-    if (m_activeSessionId.isEmpty()) return;
+    if (m_activeSessionId.isEmpty() || m_agentId.isEmpty()) return;
 
     // Re-discover agent ID — directory may have been renamed
-    QByteArray out = run9p({"ls", "session/" + m_activeSessionId + "/agent"});
+    QStringList agents = getAgents(m_activeSessionId);
-    QString agents = QString::fromUtf8(out).trimmed();
     if (agents.isEmpty()) {
         // Session or agent directory gone — don't start
         return;
     }
-    QString newId = agents.split('\n').first().trimmed();
+    QString newId = agents.first();
     if (newId != m_agentId) {
         m_agentId = newId;
         emit activeAgentIdChanged();