diff --git a/android/app/src/main/java/com/hyzq/boss/ProjectDetailActivity.java b/android/app/src/main/java/com/hyzq/boss/ProjectDetailActivity.java
index ae4eb9b..c0f2800 100644
--- a/android/app/src/main/java/com/hyzq/boss/ProjectDetailActivity.java
+++ b/android/app/src/main/java/com/hyzq/boss/ProjectDetailActivity.java
@@ -19,6 +19,7 @@ import android.view.View;
 import android.view.ViewGroup;
 import android.widget.Button;
 import android.widget.EditText;
+import android.widget.ImageButton;
 import android.widget.LinearLayout;
 import android.widget.ScrollView;
 import android.widget.TextView;
@@ -61,7 +62,7 @@ public class ProjectDetailActivity extends BossScreenActivity {
     private LinearLayout quickActionsLayout;
     private LinearLayout composerRow;
     private LinearLayout multiSelectActionsLayout;
-    private Button composerAttachmentButton;
+    private ImageButton composerAttachmentButton;
     private EditText composerInput;
     private Button composerSendButton;
     private Button multiSelectForwardButton;
@@ -105,6 +106,7 @@ public class ProjectDetailActivity extends BossScreenActivity {
     private boolean realtimeReloadRequiresFullSnapshot;
     private boolean reloadInFlight;
     private boolean pendingReload;
+    private boolean pendingReloadMessagesOnly;
     private boolean pendingReloadForcedScrollToBottom;
     private volatile boolean activityDestroyed;
     private final Runnable conversationAutoRefreshRunnable = new Runnable() {
@@ -114,7 +116,7 @@ public class ProjectDetailActivity extends BossScreenActivity {
             if (!shouldMaintainConversationAutoRefresh()) {
                 return;
             }
-            if (!reloadInFlight && !refreshLayout.isRefreshing() && shouldAutoRefreshConversation()) {
+            if (!reloadInFlight && !isComposerBusy() && shouldAutoRefreshConversation()) {
                 reload(false);
             }
             armConversationAutoRefresh();
@@ -280,6 +282,7 @@ public class ProjectDetailActivity extends BossScreenActivity {
 
         BossWindowInsets.applyKeyboardAvoidingInset(composerRow);
         BossWindowInsets.applyKeyboardAvoidingInset(multiSelectActionsLayout);
+        bindChatRefreshScrollBridge();
 
         updateProjectHeader(initialProjectName == null ? "项目详情" : initialProjectName, "正在同步项目详情...");
         if (composerAttachmentButton != null) {
@@ -352,6 +355,18 @@ public class ProjectDetailActivity extends BossScreenActivity {
         reload(false);
     }
 
+    private void bindChatRefreshScrollBridge() {
+        if (refreshLayout == null) {
+            return;
+        }
+        refreshLayout.setOnChildScrollUpCallback((parent, child) -> {
+            if (chatScrollView == null || chatScrollView.getVisibility() != View.VISIBLE) {
+                return false;
+            }
+            return chatScrollView.canScrollVertically(-1) || chatScrollView.getScrollY() > 0;
+        });
+    }
+
     void handleRealtimeEvent(BossRealtimeEvent event) {
         if (event == null || event.eventName.isEmpty() || projectId == null || projectId.isEmpty()) {
             return;
@@ -371,7 +386,7 @@ public class ProjectDetailActivity extends BossScreenActivity {
         if (tryApplyRealtimeMessagesPatch(event)) {
             return;
         }
-        runOnUiThread(() -> scheduleRealtimeReload(true));
+        runOnUiThread(() -> scheduleRealtimeReload(!"project.messages.updated".equals(event.eventName)));
     }
 
     private boolean tryApplyRealtimeMessagesPatch(BossRealtimeEvent event) {
@@ -562,6 +577,10 @@ public class ProjectDetailActivity extends BossScreenActivity {
             return;
         }
         if (reloadInFlight) {
+            pendingReloadMessagesOnly = pendingReload && pendingReloadMessagesOnly && messagesOnly;
+            if (!pendingReload) {
+                pendingReloadMessagesOnly = messagesOnly;
+            }
             pendingReload = true;
             pendingReloadForcedScrollToBottom = pendingReloadForcedScrollToBottom || forcedScrollToBottom;
             return;
@@ -641,20 +660,16 @@ public class ProjectDetailActivity extends BossScreenActivity {
             return;
         }
         boolean forcedScrollToBottom = pendingReloadForcedScrollToBottom;
+        boolean messagesOnly = pendingReloadMessagesOnly;
         pendingReload = false;
+        pendingReloadMessagesOnly = false;
         pendingReloadForcedScrollToBottom = false;
-        reload(forcedScrollToBottom);
+        reloadSnapshot(forcedScrollToBottom, messagesOnly);
     }
 
     @Override
     protected void setRefreshing(boolean refreshing) {
         super.setRefreshing(refreshing);
-        if (composerAttachmentButton != null) {
-            composerAttachmentButton.setEnabled(!refreshing && !composerSending);
-        }
-        if (composerInput != null) {
-            composerInput.setEnabled(!refreshing);
-        }
         updateComposerSendButtonState();
         updateSelectionUi();
         if (!refreshing) {
@@ -788,7 +803,7 @@ public class ProjectDetailActivity extends BossScreenActivity {
                 && shouldMaintainConversationAutoRefresh()
                 && !reloadInFlight
                 && refreshLayout != null
-                && !refreshLayout.isRefreshing()) {
+                && !isComposerBusy()) {
             reload();
         }
         updateConversationAutoRefresh();
@@ -1017,7 +1032,6 @@ public class ProjectDetailActivity extends BossScreenActivity {
     private void sendProjectMessage(String kind, String body) {
         composerSending = true;
         updateComposerSendButtonState();
-        setRefreshing(true);
         appendPendingOutgoingBubble(body);
         scrollChatToBottom();
         executor.execute(() -> {
@@ -1220,7 +1234,6 @@ public class ProjectDetailActivity extends BossScreenActivity {
     private void uploadAttachment(AttachmentComposerState.PendingAttachment attachment) {
         composerSending = true;
         updateComposerSendButtonState();
-        setRefreshing(true);
         appendPendingOutgoingAttachment(attachment);
         scrollChatToBottom();
         executor.execute(() -> {
@@ -2361,8 +2374,13 @@ public class ProjectDetailActivity extends BossScreenActivity {
         if (composerSendButton == null || composerInput == null) {
             return;
         }
+        boolean composerBusy = isComposerBusy();
+        if (composerAttachmentButton != null) {
+            composerAttachmentButton.setEnabled(!composerBusy);
+        }
+        composerInput.setEnabled(!composerBusy);
         String body = composerInput.getText() == null ? "" : composerInput.getText().toString();
-        composerSendButton.setEnabled(ProjectChatUiState.canSend(body, isComposerBusy()));
+        composerSendButton.setEnabled(ProjectChatUiState.canSend(body, composerBusy));
     }
 
     private boolean isComposerBusy() {
@@ -2698,7 +2716,6 @@ public class ProjectDetailActivity extends BossScreenActivity {
         }
         composerSending = true;
         updateComposerSendButtonState();
-        setRefreshing(true);
         showMessage(waitingMessage);
         enqueueReplyWaitPoll(waitSpec.baselineMessageId, includeDispatchPlans);
     }
@@ -2781,7 +2798,6 @@ public class ProjectDetailActivity extends BossScreenActivity {
                         if (!hasReply && !isMasterAgentConversation()) {
                             composerSending = true;
                             updateComposerSendButtonState();
-                            setRefreshing(true);
                         }
                     });
                     renderedInitialSnapshot = true;
diff --git a/android/app/src/main/res/layout/activity_project_chat.xml b/android/app/src/main/res/layout/activity_project_chat.xml
index 8613603..fcce8e5 100644
--- a/android/app/src/main/res/layout/activity_project_chat.xml
+++ b/android/app/src/main/res/layout/activity_project_chat.xml
@@ -141,18 +141,17 @@
         android:paddingRight="12dp"
         android:paddingBottom="12dp">
 
-        <Button
+        <androidx.appcompat.widget.AppCompatImageButton
             android:id="@+id/project_chat_attach"
-            android:layout_width="44dp"
-            android:layout_height="44dp"
+            android:layout_width="48dp"
+            android:layout_height="48dp"
             android:layout_marginRight="8dp"
             android:background="@drawable/bg_secondary_button"
-            android:minWidth="0dp"
-            android:text="+"
-            android:textAllCaps="false"
-            android:textColor="@color/boss_text_primary"
-            android:textSize="20sp"
-            android:textStyle="bold" />
+            android:contentDescription="发送附件"
+            android:padding="12dp"
+            android:scaleType="center"
+            android:src="@drawable/ic_boss_add"
+            android:tint="@color/boss_text_primary" />
 
         <EditText
             android:id="@+id/project_chat_input"
diff --git a/android/app/src/test/java/com/hyzq/boss/ProjectDetailActivityRealtimeTest.java b/android/app/src/test/java/com/hyzq/boss/ProjectDetailActivityRealtimeTest.java
index 84f96f6..a437e40 100644
--- a/android/app/src/test/java/com/hyzq/boss/ProjectDetailActivityRealtimeTest.java
+++ b/android/app/src/test/java/com/hyzq/boss/ProjectDetailActivityRealtimeTest.java
@@ -45,7 +45,8 @@ public class ProjectDetailActivityRealtimeTest {
         );
         Shadows.shadowOf(activity.getMainLooper()).idle();
 
-        assertEquals(1, activity.reloadCount);
+        assertEquals(0, activity.reloadCount);
+        assertEquals(1, activity.messageReloadCount);
     }
 
     @Test
@@ -131,7 +132,8 @@ public class ProjectDetailActivityRealtimeTest {
         );
         Shadows.shadowOf(activity.getMainLooper()).idle();
 
-        assertEquals(2, activity.reloadCount);
+        assertEquals(1, activity.reloadCount);
+        assertEquals(1, activity.messageReloadCount);
     }
 
     @Test
@@ -159,6 +161,7 @@ public class ProjectDetailActivityRealtimeTest {
         Shadows.shadowOf(activity.getMainLooper()).idle();
 
         assertEquals(1, activity.reloadCount);
+        assertEquals(0, activity.messageReloadCount);
     }
 
     @Test
@@ -196,7 +199,8 @@ public class ProjectDetailActivityRealtimeTest {
         );
         Shadows.shadowOf(activity.getMainLooper()).idle();
 
-        assertEquals(1, activity.reloadCount);
+        assertEquals(0, activity.reloadCount);
+        assertEquals(1, activity.messageReloadCount);
     }
 
     @Test
@@ -241,13 +245,15 @@ public class ProjectDetailActivityRealtimeTest {
         );
         Shadows.shadowOf(activity.getMainLooper()).idle();
 
-        assertEquals(1, activity.loadCallCount);
+        assertEquals(0, activity.loadCallCount);
+        assertEquals(1, activity.messageLoadCallCount);
         assertEquals(0, activity.renderCount);
 
         activity.releaseFirstLoad();
-        waitFor(() -> activity.renderCount == 2 && activity.loadCallCount == 2);
+        waitFor(() -> activity.renderCount == 2 && activity.messageLoadCallCount == 1 && activity.loadCallCount == 1);
 
-        assertEquals(2, activity.loadCallCount);
+        assertEquals(1, activity.loadCallCount);
+        assertEquals(1, activity.messageLoadCallCount);
         assertEquals(2, activity.renderCount);
     }
 
@@ -313,7 +319,9 @@ public class ProjectDetailActivityRealtimeTest {
 
     public static class TestRealtimeProjectDetailActivity extends ProjectDetailActivity {
         int reloadCount;
+        int messageReloadCount;
         volatile int loadCallCount;
+        volatile int messageLoadCallCount;
         volatile int renderCount;
         private CountDownLatch firstLoadStarted;
         private CountDownLatch releaseFirstLoad;
@@ -344,6 +352,26 @@ public class ProjectDetailActivityRealtimeTest {
             super.reload();
         }
 
+        @Override
+        ProjectSnapshot loadProjectMessagesSnapshotForRefresh() throws Exception {
+            messageReloadCount += 1;
+            messageLoadCallCount += 1;
+            if (messageLoadCallCount == 1 && firstLoadStarted != null && releaseFirstLoad != null) {
+                firstLoadStarted.countDown();
+                releaseFirstLoad.await(2, TimeUnit.SECONDS);
+            }
+            return new ProjectSnapshot(
+                    new JSONObject().put(
+                            "project",
+                            new JSONObject()
+                                    .put("name", "北区试产线")
+                                    .put("messages", new JSONArray())
+                    ),
+                    null,
+                    null
+            );
+        }
+
         @Override
         ProjectSnapshot loadProjectSnapshotForRefresh() throws Exception {
             loadCallCount += 1;
diff --git a/android/app/src/test/java/com/hyzq/boss/ProjectDetailActivityUiTest.java b/android/app/src/test/java/com/hyzq/boss/ProjectDetailActivityUiTest.java
index 6a677bf..4602f95 100644
--- a/android/app/src/test/java/com/hyzq/boss/ProjectDetailActivityUiTest.java
+++ b/android/app/src/test/java/com/hyzq/boss/ProjectDetailActivityUiTest.java
@@ -17,6 +17,7 @@ import android.widget.LinearLayout;
 import android.widget.ListView;
 import android.widget.ScrollView;
 import android.widget.TextView;
+import androidx.swiperefreshlayout.widget.SwipeRefreshLayout;
 import androidx.appcompat.app.AlertDialog;
 import org.json.JSONArray;
 import org.json.JSONObject;
@@ -131,6 +132,22 @@ public class ProjectDetailActivityUiTest {
         assertEquals(R.id.project_chat_scroll, ((View) contentLayout.getParent()).getId());
     }
 
+    @Test
+    public void chatRefreshUsesScrollViewAsChildScrollReference() {
+        Intent intent = new Intent()
+                .putExtra(ProjectDetailActivity.EXTRA_PROJECT_ID, "project-1")
+                .putExtra(ProjectDetailActivity.EXTRA_PROJECT_NAME, "北区试产线回归");
+        TestProjectDetailActivity activity = Robolectric
+                .buildActivity(TestProjectDetailActivity.class, intent)
+                .setup()
+                .get();
+
+        SwipeRefreshLayout refreshLayout = activity.findViewById(R.id.screen_refresh_layout);
+
+        Object childScrollCallback = ReflectionHelpers.getField(refreshLayout, "mChildScrollUpCallback");
+        assertNotNull(childScrollCallback);
+    }
+
     @Test
     public void composerRowLayoutChangeWithFocusedInput_scrollsChatToBottomAgain() {
         Intent intent = new Intent()
@@ -176,6 +193,48 @@ public class ProjectDetailActivityUiTest {
         assertEquals(baselineScrollCount, activity.scrollChatToBottomCount);
     }
 
+    @Test
+    public void composerBusyWithoutRefreshSpinnerStillDisablesComposerInputs() {
+        Intent intent = new Intent()
+                .putExtra(ProjectDetailActivity.EXTRA_PROJECT_ID, "project-1")
+                .putExtra(ProjectDetailActivity.EXTRA_PROJECT_NAME, "北区试产线回归");
+        TestProjectDetailActivity activity = Robolectric
+                .buildActivity(TestProjectDetailActivity.class, intent)
+                .setup()
+                .get();
+
+        ReflectionHelpers.setField(activity, "composerSending", true);
+        ReflectionHelpers.callInstanceMethod(activity, "updateComposerSendButtonState");
+
+        Button sendButton = activity.findViewById(R.id.project_chat_send);
+        View composerInput = activity.findViewById(R.id.project_chat_input);
+        View attachView = activity.findViewById(R.id.project_chat_attach);
+        SwipeRefreshLayout refreshLayout = activity.findViewById(R.id.screen_refresh_layout);
+
+        assertFalse(refreshLayout.isRefreshing());
+        assertFalse(sendButton.isEnabled());
+        assertFalse(composerInput.isEnabled());
+        assertFalse(attachView.isEnabled());
+    }
+
+    @Test
+    public void composerAttachmentUsesIconButtonFrameInsteadOfTextButton() {
+        Intent intent = new Intent()
+                .putExtra(ProjectDetailActivity.EXTRA_PROJECT_ID, "project-1")
+                .putExtra(ProjectDetailActivity.EXTRA_PROJECT_NAME, "北区试产线回归");
+        TestProjectDetailActivity activity = Robolectric
+                .buildActivity(TestProjectDetailActivity.class, intent)
+                .setup()
+                .get();
+
+        View attachView = activity.findViewById(R.id.project_chat_attach);
+
+        assertTrue(attachView instanceof ImageButton);
+        ViewGroup.LayoutParams params = attachView.getLayoutParams();
+        assertTrue(params.width >= BossUi.dp(activity, 46));
+        assertTrue(params.height >= BossUi.dp(activity, 46));
+    }
+
     @Test
     public void manualAnalysisAttachmentShowsActionChip() throws Exception {
         Intent intent = new Intent()