session pause/resume UI

- Add Pause/Resume toggle to session context menu
- Gray agent dots when parent session is paused
- Disable input field with 'Session paused' placeholder when paused
- Preserve focus on prompt input during tree rebuilds

gui/main.qml

@@ -108,6 +108,8 @@ ApplicationWindow {
 
     function buildSessionTree() {
         console.log("buildSessionTree: sessions count = " + ollie.sessions.length)
+        // Preserve focus if prompt input has it
+        var hadFocus = promptInput.activeFocus
         sessionTreeModel.clear()
         var sessions = ollie.sessions
         for (var i = 0; i < sessions.length; ++i) {
@@ -147,6 +149,9 @@ ApplicationWindow {
             }
         }
         console.log("  total tree items: " + sessionTreeModel.count)
+        // Restore focus if it was on the prompt input
+        if (hadFocus)
+            promptInput.forceActiveFocus()
     }
 
     function toggleExpand(index) {
@@ -702,6 +707,17 @@ ApplicationWindow {
                                     newAgentDialog.open()
                                 }
                             }
+                            MenuItem {
+                                text: ollie.isSessionPaused(root.killTargetSessionId) ? "Resume" : "Pause"
+                                onClicked: {
+                                    if (root.killTargetSessionId) {
+                                        if (ollie.isSessionPaused(root.killTargetSessionId))
+                                            ollie.resumeSession(root.killTargetSessionId)
+                                        else
+                                            ollie.pauseSession(root.killTargetSessionId)
+                                    }
+                                }
+                            }
                             MenuItem {
                                 text: "Kill Session"
                                 onClicked: {
@@ -805,6 +821,9 @@ ApplicationWindow {
                                     if (cc === "red") return "#f44336"
                                     return "#9e9e9e"
                                 }
+                                // Agent: check if parent session is paused
+                                if (ollie.isSessionPaused(parentId))
+                                    return "#9e9e9e"  // gray when paused
                                 // Agent: execution state - query live state
                                 var s = ollie.agentState(parentId, agentId) || "idle"
                                 if (s === "idle") return "#4caf50"
@@ -1052,8 +1071,13 @@ property bool blockExpanded: {
                     TextArea {
                         id: promptInput
                         Layout.fillWidth: true
-                        placeholderText: !ollie.activeSessionId ? "No session" : !ollie.activeAgentId ? "No agent" : "Message..."
-                        enabled: ollie.activeSessionId !== "" && ollie.activeAgentId !== ""
+                        placeholderText: {
+                            if (!ollie.activeSessionId) return "No session"
+                            if (!ollie.activeAgentId) return "No agent"
+                            if (ollie.isSessionPaused(ollie.activeSessionId)) return "Session paused"
+                            return "Message..."
+                        }
+                        enabled: ollie.activeSessionId !== "" && ollie.activeAgentId !== "" && !ollie.isSessionPaused(ollie.activeSessionId)
                         wrapMode: TextEdit.Wrap
 
                         property string _lastText: ""

gui/ollie9pclient.cpp

@@ -538,6 +538,50 @@ bool Ollie9pClient::killSession(const QString &sessionId)
     return proc.exitCode() == 0;
 }
 
+bool Ollie9pClient::pauseSession(const QString &sessionId)
+{
+    if (sessionId.isEmpty()) return false;
+    QString path = "session/" + sessionId + "/ctl";
+    QProcess proc;
+    proc.start(ninepBin(), {"-a", serverAddr(), "write", path});
+    proc.waitForStarted(3000);
+    proc.write("pause");
+    proc.closeWriteChannel();
+    proc.waitForFinished(3000);
+    if (proc.exitCode() == 0) {
+        refreshSessions();
+        return true;
+    }
+    return false;
+}
+
+bool Ollie9pClient::resumeSession(const QString &sessionId)
+{
+    if (sessionId.isEmpty()) return false;
+    QString path = "session/" + sessionId + "/ctl";
+    QProcess proc;
+    proc.start(ninepBin(), {"-a", serverAddr(), "write", path});
+    proc.waitForStarted(3000);
+    proc.write("resume");
+    proc.closeWriteChannel();
+    proc.waitForFinished(3000);
+    if (proc.exitCode() == 0) {
+        refreshSessions();
+        return true;
+    }
+    return false;
+}
+
+bool Ollie9pClient::isSessionPaused(const QString &sessionId) const
+{
+    for (const QVariant &v : m_sessions) {
+        const QVariantMap s = v.toMap();
+        if (s.value("id").toString() == sessionId)
+            return s.value("paused").toBool();
+    }
+    return false;
+}
+
 QString Ollie9pClient::getConfig()
 {
     if (m_activeSessionId.isEmpty()) return {};

gui/ollie9pclient.h

@@ -67,6 +67,9 @@ public:
     Q_INVOKABLE bool interrupt();
     Q_INVOKABLE bool kill();
     Q_INVOKABLE bool killSession(const QString &sessionId);
+    Q_INVOKABLE bool pauseSession(const QString &sessionId);
+    Q_INVOKABLE bool resumeSession(const QString &sessionId);
+    Q_INVOKABLE bool isSessionPaused(const QString &sessionId) const;
     Q_INVOKABLE QString getConfig();
     Q_INVOKABLE QStringList getAgents(const QString &sessionId);