fix: keep scroll lock user-controlled during thinking

static/src/composables/useLegacySocket.ts

@@ -835,7 +835,6 @@ export async function initializeLegacySocket(ctx: any) {
             streamingState.activeTextAction = null;
             ctx.stopRequested = false;
             ctx.streamingMessage = true; // 确保设置为流式状态
-            ctx.chatEnableAutoScroll();
             ctx.scrollToBottom();
         });
 
@@ -853,8 +852,7 @@ export async function initializeLegacySocket(ctx: any) {
             if (result && result.blockId) {
                 const blockId = result.blockId;
                 ctx.chatExpandBlock(blockId);
-                // 开始思考时自动锁定滚动到底部
-                ctx.chatEnableAutoScroll();
+                // 开始思考时尝试滚动到底部，但不改变用户锁定选择
                 ctx.scrollToBottom();
                 ctx.chatSetThinkingLock(blockId, true);
                 ctx.$forceUpdate();