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/chat/ChatInput.tsx

@@ -431,7 +431,7 @@ const PermissionAutoAcceptButton = React.memo(function PermissionAutoAcceptButto
     }
 
     return (
-        <Tooltip delayDuration={600}>
+        <Tooltip>
             <TooltipTrigger asChild>
                 {button}
             </TooltipTrigger>
@@ -454,7 +454,7 @@ const FocusModeButton = React.memo(function FocusModeButton(props: FocusModeButt
     const { t } = useI18n();
 
     return (
-        <Tooltip delayDuration={600}>
+        <Tooltip>
             <TooltipTrigger asChild>
                 <button
                     type="button"