DBX SSH plugin 0.7.5

SFTP 大目录滚动、弹窗窄视口、文本预览选区与 Docker 面板四处修复 / Four fixes: SFTP large-directory scrolling, narrow-viewport dialogs, preview selection color, Docker table layout — codex/ssh/release-0.7.5-beta.2 @ d2185b9

0.7.5 正式版。内容与 0.7.5-beta.2 / 0.7.5-beta.3 两个预发布完全一致（基于 0.7.4 的四处 bug 修复线；不含 scheduler 任务功能——该功能需宿主侧配套，待 DBX 支持后在 main 上另行发版），经 beta 验证后仅版本号转正。五平台 .dbxp 与 release-candidates.json 由 CI 在本 Release 上自动构建上传；安装走插件中心或 scripts/install.sh（安装与 DBX 重启为人工动作）。

修复 / Fixed

• SFTP 大目录滚动（#151）：文件较多时鼠标滚动失效、列表展示不全——虚拟滚动的窗口 spacer 与行列表被 v-else 写成互斥，滚过前几行后整个行列表不再渲染；现在 spacer 与行并存，滚到底最后一个文件可见，并新增 2000 行大目录 mock 夹具与 App.vue 源码结构守卫用例防回归。
  SFTP large-directory scrolling (#151). With many files, wheel scrolling died and the list was cut off — the virtual-scroll window spacer and the row list were wrongly paired with v-else, so the entire row list stopped rendering past the first few rows. Spacer and rows now coexist and the last file is reachable, with a 2000-row mock fixture and a source-structure guard test to prevent regressions.
• 弹窗窄视口溢出（#153）：窗口较窄时弹窗右半偏出屏幕——DialogContent 定位器是 grid 但未定义轨道，弹窗百分比宽度按内容尺寸解析、收缩失效；定位器显式 minmax(0, 1fr) 列/行轨道后，所有弹窗在窄视口正确收缩并保持居中，宽视口行为不变。
  Narrow-viewport dialog overflow (#153). On narrower windows dialogs had their right half pushed off-screen — the DialogContent positioner was a grid with no explicit tracks, so the percentage width resolved against content size and never clamped; explicit minmax(0, 1fr) tracks shrink and center every dialog, unchanged at wide viewports.
• 文本预览选区色（#155）：打开文本文件后鼠标选取的高亮与背景几乎无法区分（亮色主题对比度仅 ~1.2:1）——明暗两套选区色加深并提高不透明度，选中范围清晰可辨。
  Text-preview selection color (#155). The mouse-selection highlight in an opened text file was nearly indistinguishable from the background (~1.2:1 contrast on the light theme); both light and dark selection colors are deepened with higher opacity.
• Docker 面板表格布局：列内容过宽时横向滚动条被全局隐藏规则吞掉、操作列的下拉按钮被内容推出视口——溢出时滚动条显式可见可拖；容器名首列与操作末列改为粘性列（滚动中名称固定靠左、按钮固定靠右永不被遮挡，粘性列带浮层同底色与 1px 分隔缘）；表格切 separate 边框模型保证 Firefox 粘性单元格边框正确绘制。
  Docker panel table layout. With wide content the horizontal scrollbar was swallowed by the global scrollbar-hiding rule and the row actions' dropdown trigger was pushed out of view — the scrollbar is now explicitly visible on overflow; the container-name first column is sticky-left and the actions last column sticky-right, each on an opaque popover background with a 1px separator edge; the table uses the separate border model so Firefox paints sticky-cell borders correctly.

完整变更见 CHANGELOG.md。