targeted state dot updates in render path

- onAgentStateChanged: update specific agent in model instead of version bump
- State dot: use model.state directly instead of ollie.agentState() callback
- Remove ollie.isSessionPaused() call (was O(n) iteration per agent)
- Remove unused agentStateVersion property

Before: 1 state change → re-evaluate ALL agent dots → N * ollie.agentState() calls
After:  1 state change → setProperty on 1 model item → 1 binding update

gui/main.qml

@@ -11,9 +11,6 @@ ApplicationWindow {
     font.family: theme.fontFamily || Qt.application.font.family
     font.pointSize: theme.fontSize > 0 ? theme.fontSize : Qt.application.font.pointSize
 
-    // Version counter to force re-evaluation of agent state colors
-    property int agentStateVersion: 0
-
     // Apply theme palette to all Qt Quick Controls
     palette.active.window: theme.windowColor
     palette.active.windowText: theme.windowTextColor
@@ -386,8 +383,14 @@ ApplicationWindow {
             }
         }
         function onAgentStateChanged(sessionId, agentId, state) {
-            // Increment version to force re-evaluation of all agent state colors
-            root.agentStateVersion++
+            // Update only the specific agent in the model (avoids re-evaluating all)
+            for (var i = 0; i < sessionTreeModel.count; ++i) {
+                var item = sessionTreeModel.get(i)
+                if (item.type === "agent" && item.parentId === sessionId && item.agentId === agentId) {
+                    sessionTreeModel.setProperty(i, "state", state)
+                    break
+                }
+            }
         }
     }
 
@@ -979,10 +982,7 @@ ApplicationWindow {
                             Layout.preferredHeight: 8
                             Layout.alignment: Qt.AlignVCenter
                             radius: 4
-                            property int stateVersion: root.agentStateVersion
                             color: {
-                                // Depend on stateVersion to force re-evaluation
-                                void(stateVersion)
                                 if (type === "session") {
                                     // Session: RPC connection health
                                     var cc = connectionColor || "gray"
@@ -991,11 +991,8 @@ 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"
+                                // Agent: use state from model (already updated via onAgentStateChanged)
+                                var s = model.state || "idle"
                                 if (s === "idle") return "#4caf50"
                                 if (s.startsWith("calling")) return "#ff9800"
                                 return "#2196f3"