gui: smart auto-scroll follows streaming content

- Add shouldAutoScroll property to track user intent
- Auto-scroll when near bottom (within 50px threshold)
- Disable auto-scroll when user scrolls up to read history
- Re-enable when user scrolls back to bottom
- Reset to auto-scroll on session/agent switch
- Increase timer interval to 16ms for smoother layout settling

gui/main.qml

@@ -96,9 +96,12 @@ ApplicationWindow {
     // Deferred scroll timer — fires once after model changes settle
     Timer {
         id: scrollTimer
-        interval: 0
+        interval: 16  // ~1 frame at 60fps, allows layout to settle
         repeat: false
-        onTriggered: chatView.positionViewAtEnd()
+        onTriggered: {
+            if (chatView.shouldAutoScroll)
+                chatView.positionViewAtEnd()
+        }
     }
 
     // Session ID to kill — set on right-click, consumed by context menu
@@ -485,6 +488,7 @@ ApplicationWindow {
         target: ollie
         function onActiveSessionIdChanged() {
             chatModel.reset()
+            chatView.shouldAutoScroll = true  // Reset scroll state on session switch
             if (ollie.activeSessionId && ollie.activeAgentId) {
                 var log = ollie.readLogForSession(ollie.activeSessionId, ollie.activeAgentId)
                 if (log) {
@@ -496,6 +500,7 @@ ApplicationWindow {
         }
         function onActiveAgentIdChanged() {
             chatModel.reset()
+            chatView.shouldAutoScroll = true  // Reset scroll state on agent switch
             if (ollie.activeSessionId && ollie.activeAgentId) {
                 var log = ollie.readLogForSession(ollie.activeSessionId, ollie.activeAgentId)
                 if (log) {
@@ -1244,15 +1249,32 @@ ApplicationWindow {
                     boundsBehavior: Flickable.StopAtBounds
                     visible: ollie.daemonConnected && ollie.activeAgentId !== ""
 
+                    // Auto-scroll when near bottom (within ~50px or at end)
+                    // Reset to true on new blocks, user can scroll up to disable
+                    property bool shouldAutoScroll: true
+                    readonly property bool nearBottom: contentHeight - contentY - height < 50
+
+                    onContentYChanged: {
+                        // User scrolled up - disable auto-scroll
+                        // User scrolled to bottom - re-enable
+                        if (dragging || flicking) {
+                            shouldAutoScroll = nearBottom || atYEnd
+                        }
+                    }
+
                     onCountChanged: {
-                        if (count > 0)
-                            scrollTimer.start()
+                        // New block added - always scroll if we were following
+                        if (count > 0) {
+                            if (shouldAutoScroll)
+                                scrollTimer.start()
+                        }
                     }
 
                     Connections {
                         target: chatModel
                         function onDataChanged() {
-                            if (chatView.atYEnd && chatView.count > 0)
+                            // Content updated (streaming) - scroll if following
+                            if (chatView.shouldAutoScroll && chatView.count > 0)
                                 scrollTimer.start()
                         }
                     }