feat：添加随屏滚动+优化底部占位盒子高度

components/ChatWindow.tsx

@@ -224,6 +224,11 @@ export function ChatWindow({ session, newSessionCwd, onAgentEnd, onSessionCreate
     soundedExtensionDialogIdRef.current = extensionDialog.id;
     playDoneSoundRef.current();
   }, [extensionDialog]);
+
+  // Reserve enough bottom padding in the message list so the last message is
+  // not hidden behind the fixed ChatInput. The input area's minimum height is
+  // ~52px (textarea + padding + bottom controls), so we keep a static spacer.
+  const inputHeight = 52;
 
   // Register the abort handler for the global Esc shortcut
   useEffect(() => {
@@ -719,9 +724,9 @@ export function ChatWindow({ session, newSessionCwd, onAgentEnd, onSessionCreate
               />
             )}
 
-            {agentRunning && (
-              <div style={{ height: scrollContainerRef.current ? scrollContainerRef.current.clientHeight : "80vh" }} />
-            )}
+            {/* Spacer sized to the bottom input area so the last message is
+                not hidden behind ChatInput, without wasting a full viewport. */}
+            <div style={{ height: inputHeight }} />
 
             <div ref={messagesEndRef} />
             </div>

hooks/useAgentSession.ts

@@ -156,6 +156,10 @@ export type ThinkingLevelOption = "auto" | "off" | "minimal" | "low" | "medium"
 
 const PROGRAMMATIC_SCROLL_IGNORE_MS = 700;
 const USER_SCROLL_INTENT_MS = 1200;
+// Distance from the bottom of the scroll container within which live-follow
+// scrolling is active. Larger values make follow more lenient; smaller values
+// require the user to stay closer to the bottom.
+const SCROLL_BOTTOM_THRESHOLD = 150;
 const PROMPT_SETTLE_INITIAL_DELAY_MS = 800;
 const PROMPT_SETTLE_POLL_MS = 600;
 const PROMPT_SETTLE_MAX_MS = 20_000;
@@ -396,6 +400,7 @@ export function useAgentSession(opts: UseAgentSessionOptions) {
   const lastUserMsgRef = useRef<HTMLDivElement | null>(null);
   const pendingScrollToUserRef = useRef(false);
   const completionScrollAllowedRef = useRef(true);
+  const isNearBottomRef = useRef(true);
   const executeBashRef = useRef<(command: string, excludeFromContext: boolean) => Promise<void> | undefined>(undefined);
   const userScrollIntentUntilRef = useRef(0);
   const ignoreProgrammaticScrollUntilRef = useRef(0);
@@ -1129,6 +1134,13 @@ export function useAgentSession(opts: UseAgentSessionOptions) {
           dispatch({ type: "update", message: normalizeToolCalls(msg as AgentMessage) });
         }
         setAgentPhase(null);
+        // Live-follow the streaming output only when the user is already near
+        // the bottom of the message list. If they scrolled up, leave them there.
+        if (isNearBottomRef.current) {
+          // Defer the scroll so React has time to update the DOM with the new
+          // streaming content; otherwise scrollIntoView may target stale layout.
+          requestAnimationFrame(() => scrollToBottom("auto"));
+        }
         break;
       }
       case "message_end": {
@@ -1703,6 +1715,11 @@ export function useAgentSession(opts: UseAgentSessionOptions) {
   }, []);
 
   const handleScrollPositionChange = useCallback(() => {
+    const container = scrollContainerRef.current;
+    if (container) {
+      const { scrollTop, clientHeight, scrollHeight } = container;
+      isNearBottomRef.current = scrollTop + clientHeight >= scrollHeight - SCROLL_BOTTOM_THRESHOLD;
+    }
     if (!agentRunningRef.current) return;
     if (Date.now() < ignoreProgrammaticScrollUntilRef.current) return;
     if (Date.now() > userScrollIntentUntilRef.current) return;
@@ -1793,7 +1810,7 @@ export function useAgentSession(opts: UseAgentSessionOptions) {
       } else if (!initialScrollDoneRef.current) {
         initialScrollDoneRef.current = true;
         scrollToBottom("instant");
-      } else if (!agentRunningRef.current && completionScrollAllowedRef.current) {
+      } else if (!agentRunningRef.current && (completionScrollAllowedRef.current || isNearBottomRef.current)) {
         scrollToBottom("smooth");
       }
     }