feat(styles): mark the current style with a ✓ in the list

Every style manager now shows a leading ✓ next to the current style
(current text/dim style, active table/multileader/multiline style), with
the other rows padded so names stay aligned. The marker replaces the
multileader/multiline-only ◀ and is wired for all five managers by
threading the current-style name into each view.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/ui/dimstyle.rs

@@ -184,6 +184,7 @@ fn hdivider<'a>() -> Element<'a, Message> {
 pub fn view_window<'a>(
     styles: Vec<String>,
     selected: &'a str,
+    current: &'a str,
     tab: u8,
     vals: DimStyleValues<'a>,
     rename_active: Option<&'a str>,
@@ -724,7 +725,7 @@ pub fn view_window<'a>(
         kind: crate::app::StyleKind::Dim,
         styles: &styles,
         selected,
-        current: None,
+        current: Some(current),
         rename_active,
         rename_buf,
         on_new: Message::DimStyleDialogNew,