fix(web): 转发选择器好友/群聊分开全选

原来是列表整体一个全选按钮，选中后好友和群聊会一起被勾上。改成
好友、群聊两个分组各自独立的全选/取消全选，互不影响，方便只想
批量选中其中一类的场景（比如只发给所有群，不带上私聊好友）。

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

web/src/features/messages/ForwardPickerModal.tsx

@@ -55,18 +55,23 @@ export function ForwardPickerModal({ onPick, onClose }: ForwardPickerModalProps)
     });
   };
 
-  const visibleTopics = useMemo(() => filtered.map((c) => c.topic).filter((t): t is string => !!t), [filtered]);
-  const allVisibleSelected = visibleTopics.length > 0 && visibleTopics.every((t) => selected.has(t));
-  const toggleSelectAll = () => {
+  // 好友/群聊各自独立的全选 -- 一次转发常常只想覆盖其中一类（比如"发给所有群"但不想带上私聊
+  // 好友），一个笼统的全选做不到这一点，所以拆成两个独立开关而不是列表整体一个。
+  const friendTopics = useMemo(() => friends.map((c) => c.topic).filter((t): t is string => !!t), [friends]);
+  const groupTopics = useMemo(() => groups.map((c) => c.topic).filter((t): t is string => !!t), [groups]);
+  const allFriendsSelected = friendTopics.length > 0 && friendTopics.every((t) => selected.has(t));
+  const allGroupsSelected = groupTopics.length > 0 && groupTopics.every((t) => selected.has(t));
+
+  const toggleSectionSelectAll = (topics: string[], allSelected: boolean) => {
     setSelected((prev) => {
-      if (allVisibleSelected) {
+      if (allSelected) {
         // Only drop the ones the CURRENT search actually shows -- a selection made under an earlier,
         // now-cleared query shouldn't be wiped out by un-selecting "all" of a narrower view.
         const next = new Set(prev);
-        for (const t of visibleTopics) next.delete(t);
+        for (const t of topics) next.delete(t);
         return next;
       }
-      return new Set([...prev, ...visibleTopics]);
+      return new Set([...prev, ...topics]);
     });
   };
 
@@ -121,22 +126,35 @@ export function ForwardPickerModal({ onPick, onClose }: ForwardPickerModalProps)
               className="ml-2 w-full bg-transparent text-sm outline-none placeholder:text-text-placeholder-2"
             />
           </div>
-          {visibleTopics.length ? (
-            <button type="button" onClick={toggleSelectAll} className="mt-2 text-xs text-accent">
-              {allVisibleSelected ? '取消全选' : '全选'}
-            </button>
-          ) : null}
         </div>
         <div className="flex-1 overflow-y-auto px-2 py-2">
           {friends.length ? (
             <>
-              <div className="px-3 pb-1 pt-2 text-xs text-text-tertiary-2">好友</div>
+              <div className="flex items-center justify-between px-3 pb-1 pt-2">
+                <span className="text-xs text-text-tertiary-2">好友</span>
+                <button
+                  type="button"
+                  onClick={() => toggleSectionSelectAll(friendTopics, allFriendsSelected)}
+                  className="text-xs text-accent"
+                >
+                  {allFriendsSelected ? '取消全选' : '全选'}
+                </button>
+              </div>
               {friends.map(renderRow)}
             </>
           ) : null}
           {groups.length ? (
             <>
-              <div className="px-3 pb-1 pt-2 text-xs text-text-tertiary-2">群聊</div>
+              <div className="flex items-center justify-between px-3 pb-1 pt-2">
+                <span className="text-xs text-text-tertiary-2">群聊</span>
+                <button
+                  type="button"
+                  onClick={() => toggleSectionSelectAll(groupTopics, allGroupsSelected)}
+                  className="text-xs text-accent"
+                >
+                  {allGroupsSelected ? '取消全选' : '全选'}
+                </button>
+              </div>
               {groups.map(renderRow)}
             </>
           ) : null}