fix: keep browser overlays and knowledge controls usable

Native browser pages could cover application dialogs and overlapping menus
or notifications. Suspend only the viewport while covered and restore the
same active page afterward, including nested dialogs and terminal prompts.

Keep knowledge source controls at their full height, constrain long library
cards and titles, and update automatic names when switching remote targets
without overwriting edited or saved names. Restore packaged release-note
loading now that the history exceeds its previous size limit.

Add focused regressions and real Electron UI evidence. Clean up temporary
Harness fixture directories at test completion instead of accumulating them.

Release note: 修复内嵌浏览器遮挡弹窗和浮层、知识库来源选项被压缩及长名称显示异常；切换远端知识库时自动名称正确更新，并恢复更新说明显示。

docs/features/knowledge-base/ui-design.md

@@ -25,6 +25,11 @@
 标题区提供“用于当前对话”“检索测试”、编辑和删除。新建知识库是页面主操作。
 “高级设置”承载问答效果入口、向量索引、分块与图谱配置，不把工程参数放在首次路径。
 
+本地与外部库共用的列表以 `minmax(0, 1fr)` 限制条目宽度，再对名称单行省略；选中卡片
+的边框必须完整留在列表内，Provider/实例等辅助文字允许换行。不得用列表外层裁切
+掩盖被长名称撑宽的卡片，库图标不能随名称一起收缩。外部详情的长名称和远端名称允许
+换行，不能撑出横向滚动条。创建类型分段控件与详情页签保持固定内容高度，不随长表单收缩。
+
 ## 3. 首次使用
 
 没有知识库时，页面空状态显示“新建知识库”主操作。创建时先选择类型；本地类型默认