fix(gui): improve multi-agent-per-session handling

Session selection now auto-selects first agent:
- Clicking a session row selects its first agent (not just the session)
- Auto-select at startup now picks first agent of first session
- Fixes issue where clicking session would clear agent and show empty chat

Improved UI feedback:
- Header shows 'Session / Agent' name instead of just state
- State indicator gray when no agent selected
- Placeholder message when no agent selected: 'Select an agent to view chat'
- Chat ListView hidden when no agent (shows placeholder instead)
- Input already disabled with 'No agent' placeholder (existing behavior)

Cleanup:
- Remove dead declaration reconcileAgentConnections(const QVariantList&)

gui/main.qml

@@ -627,7 +627,22 @@ ApplicationWindow {
                             }
                             if (renamingIndex >= 0) return
                             if (type === "session") {
-                                ollie.setActiveSessionId(id)
+                                // Find first agent in this session and select it
+                                var foundAgent = null
+                                for (var i = 0; i < sessionTreeModel.count; ++i) {
+                                    var item = sessionTreeModel.get(i)
+                                    if (item.type === "agent" && item.parentId === id) {
+                                        foundAgent = item
+                                        break
+                                    }
+                                }
+                                if (foundAgent) {
+                                    // Select the first agent
+                                    activateAgent(id, foundAgent.agentId)
+                                } else {
+                                    // No agents - just select session (clears agent)
+                                    ollie.setActiveSessionId(id)
+                                }
                                 toggleExpand(parent.modelIndex)
                             } else if (type === "agent") {
                                 activateAgent(parentId, agentId)
@@ -773,15 +788,44 @@ ApplicationWindow {
         ColumnLayout {
             spacing: 0
 
-            // Header
+            // Header - shows active session/agent and state
             RowLayout {
                 Layout.fillWidth: true
                 Layout.margins: 6
                 spacing: 8
 
+                // Active session/agent label
+                Label {
+                    text: {
+                        var sessionName = ""
+                        var agentName = ""
+                        for (var i = 0; i < sessionTreeModel.count; ++i) {
+                            var item = sessionTreeModel.get(i)
+                            if (item.type === "session" && item.id === ollie.activeSessionId) {
+                                sessionName = item.displayName || item.id
+                            }
+                            if (item.type === "agent" && item.agentId === ollie.activeAgentId && item.parentId === ollie.activeSessionId) {
+                                agentName = item.displayName || item.agentId
+                            }
+                        }
+                        if (sessionName && agentName) {
+                            return sessionName + " / " + agentName
+                        } else if (sessionName) {
+                            return sessionName + " (no agent)"
+                        }
+                        return "(no session)"
+                    }
+                    font.bold: true
+                    font.pointSize: theme.fontSize > 0 ? theme.fontSize : Qt.application.font.pointSize
+                    elide: Text.ElideMiddle
+                    Layout.fillWidth: true
+                }
+
+                // State indicator
                 Rectangle {
                     width: 10; height: 10; radius: 5
                     color: {
+                        if (!ollie.activeAgentId) return "#9e9e9e"  // gray when no agent
                         if (ollie.activeState === "idle") return "#4caf50"
                         if (ollie.activeState.startsWith("calling")) return "#ff9800"
                         return "#2196f3"
@@ -789,12 +833,10 @@ ApplicationWindow {
                 }
 
                 Label {
-                    text: ollie.activeState
+                    text: ollie.activeAgentId ? ollie.activeState : ""
                     opacity: 0.7
                     font.pointSize: theme.fontSize > 0 ? theme.fontSize * 0.85 : 11
                 }
-
-                Item { Layout.fillWidth: true }
             }
 
             Rectangle { Layout.fillWidth: true; height: 1; color: theme.midColor }
@@ -805,6 +847,16 @@ ApplicationWindow {
                 Layout.fillHeight: true
                 clip: true
 
+                // Placeholder when no agent selected
+                Label {
+                    anchors.centerIn: parent
+                    text: ollie.activeSessionId ? "Select an agent to view chat" : "Select a session"
+                    color: theme.midColor
+                    font.italic: true
+                    font.pixelSize: theme.fontSize > 0 ? theme.fontSize : 12
+                    visible: !ollie.activeAgentId
+                }
+
                 ListView {
                     id: chatView
                     model: chatModel
@@ -812,6 +864,7 @@ ApplicationWindow {
                     anchors.fill: parent
                     anchors.margins: 4
                     boundsBehavior: Flickable.StopAtBounds
+                    visible: ollie.activeAgentId !== ""
 
                     onCountChanged: {
                         if (count > 0)

gui/ollie9pclient.cpp

@@ -330,9 +330,19 @@ void Ollie9pClient::refreshSessions()
 	reconcileAgentConnections();
 	emit sessionsChanged();
 
-	// Auto-select first session if none active
+	// Auto-select first session and its first agent if none active
 	if (m_activeSessionId.isEmpty() && !m_sessions.isEmpty()) {
-		setActiveSessionId(m_sessions.first().toMap()["id"].toString());
+		const QVariantMap firstSession = m_sessions.first().toMap();
+		const QString sid = firstSession.value("id").toString();
+		const QVariantList agents = firstSession.value("agents").toList();
+		if (!agents.isEmpty()) {
+			// Select first agent of first session
+			const QString aid = agents.first().toMap().value("id").toString();
+			switchAgent(sid, aid);
+		} else {
+			// No agents - just select the session
+			setActiveSessionId(sid);
+		}
 	}
 }
 

gui/ollie9pclient.h

@@ -76,7 +76,6 @@ public:
     };
 
     QList<AgentRecord> readAgentRecords(const QString &sessionId);
-    void reconcileAgentConnections(const QVariantList &sessions);
     void setAgentConnected(const QString &key, bool connected);
     QString agentKey(const QString &sessionId, const QString &agentId) const;
     Q_INVOKABLE void setActiveAgentId(const QString &agentId);