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/session/sidebar/sortableItems.tsx

@@ -166,7 +166,7 @@ export const SortableProjectItem: React.FC<SortableProjectItemProps> = ({
             style={{ backgroundColor: isDesktopShell && isStuck ? 'transparent' : undefined }}
           >
             <div className="relative flex items-center gap-1 px-0.5 py-0.5" {...attributes}>
-              <Tooltip delayDuration={1500}>
+              <Tooltip>
                 <TooltipTrigger asChild>
                     <button
                       type="button"