feat(ui): unify overlay animations and trim tooltip delays

Use base-ui's transition-status pattern (data-starting-style /
data-ending-style) for Dialog, DropdownMenu, Select, Tooltip and Popover
so open/close animate consistently at 150ms ease-out without flicker.
Wrap dialog popups in a centered flex container so the scale animation
no longer fights with translate-based positioning, and switch
PendingChangesBar to a real Popover so it actually animates closed.

Convert ScheduledTaskEditorDialog from raw Radix to the shared Dialog
wrapper, give ScheduledTasksDialog a stable min-height to prevent layout
shift mid-animation, and reset NewWorktreeDialog form state on open
instead of close so fields don't empty during the close transition.

Drop tooltip delay from 700ms to 300ms globally and remove all
per-component overrides except the model/variant/agent selectors in the
chat input (600ms).

packages/ui/src/components/views/git/HistoryCommitRow.tsx

@@ -88,7 +88,7 @@ export const HistoryCommitRow = React.memo(({
             <code className="shrink-0 font-mono">
               {entry.hash.slice(0, 8)}
             </code>
-            <Tooltip delayDuration={500}>
+            <Tooltip>
               <TooltipTrigger asChild>
                 <Button
                   variant="ghost"