feat(ui): shared ListPane primitive + misc polish

ListPane is a compound component (Header / TitleRow / Title / Actions /
Search / Scroll) that owns the relative wrapper, faded right divider
(50px top fade), top scroll mask, and absolute-positioned header used by
every list-detail tab. Wires up CapturesTab, StoryList, and EffectsList.
EffectsTab gets -mx-8 / pr-8 to match the edge-to-edge layout used
elsewhere.

Other changes:
- MCPPage: native <select> → shadcn <Select> for default voice and
  per-binding voice pickers
- Button outline variant: add hover:border-accent
- Drop hover:text-destructive from trailing delete buttons
  (HistoryTable, GpuAcceleration, GpuPage, EffectsChainEditor,
  EffectsDetail)
- HistoryTable empty state moved behind t('history.empty')
- StoryContent scroll padding pt-14 → pt-16
- backend health reports the captures dir
- landing CapturesMockup: "Send to" → "Export" with Download icon
- CHANGELOG: drop [Unreleased] personality section

app/src/components/ServerTab/GpuPage.tsx

@@ -388,7 +388,7 @@ export function GpuPage() {
                       onClick={handleDelete}
                       variant="ghost"
                       size="sm"
-                      className="text-muted-foreground hover:text-destructive"
+                      className="text-muted-foreground "
                     >
                       <Trash2 className="h-3.5 w-3.5 mr-1.5" />
                       {t('settings.gpu.remove.button')}