feat(share): reuse existing share and direct links per file

frontend/app.js

@@ -2497,12 +2497,18 @@ handleDragLeave(e) {
         if (response.data.success) {
           const itemType = this.shareFileForm.isDirectory ? '文件夹' : '文件';
           this.shareResult = this.buildShareResult(response.data, {
-            hasPassword: this.shareFileForm.enablePassword,
+            hasPassword: !!response.data.has_password,
             targetName: this.shareFileForm.fileName,
             targetType: shareType,
-            password
+            password: response.data.reused ? '' : password
           });
-          this.showToast('success', '成功', this.shareFileForm.enablePassword ? `${itemType}加密分享已创建` : `${itemType}分享链接已创建`);
+          this.showToast(
+            'success',
+            '成功',
+            response.data.reused
+              ? `${itemType}已复用现有分享链接`
+              : (this.shareFileForm.enablePassword ? `${itemType}加密分享已创建` : `${itemType}分享链接已创建`)
+          );
           this.loadShares();
         }
       } catch (error) {
@@ -2551,7 +2557,7 @@ handleDragLeave(e) {
             ...response.data,
             target_name: this.directLinkForm.fileName
           };
-          this.showToast('success', '成功', '直链已创建');
+          this.showToast('success', '成功', response.data.reused ? '已复用现有直链' : '直链已创建');
           this.loadDirectLinks();
         }
       } catch (error) {