fix(virtual_list): Borde completo + centrado texto

- Añadir borde alrededor de toda la lista (siempre visible)
- Mejorar centrado vertical del texto (y+4 → y+3)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/widgets/virtual_list/virtual_list.zig

@@ -173,7 +173,10 @@ pub fn virtualListRect(
         drawScrollbar(ctx, bounds, header_h, footer_h, list_state, visible_rows, total_rows, &colors);
     }
 
-    // Draw focus ring
+    // Draw border around the entire list (always visible)
+    ctx.pushCommand(Command.rectOutline(bounds.x, bounds.y, bounds.w, bounds.h, colors.border));
+
+    // Draw focus ring (additional highlight when focused)
     if (has_focus) {
         if (Style.isFancy()) {
             ctx.pushCommand(Command.focusRing(bounds.x, bounds.y, bounds.w, bounds.h, 4));
@@ -259,7 +262,7 @@ fn drawHeader(
         // Column title
         ctx.pushCommand(Command.text(
             x + 4,
-            bounds.y + 4,
+            bounds.y + 3, // Centrado vertical mejorado
             col.title,
             colors.text,
         ));
@@ -270,7 +273,7 @@ fn drawHeader(
                 const indicator = list_state.sort_direction.symbol();
                 ctx.pushCommand(Command.text(
                     x + @as(i32, @intCast(col.width)) - 20,
-                    bounds.y + 4,
+                    bounds.y + 3, // Centrado vertical mejorado
                     indicator,
                     colors.text,
                 ));
@@ -366,7 +369,7 @@ fn drawRows(
 
                 ctx.pushCommand(Command.text(
                     x + 4,
-                    row_y + 4,
+                    row_y + 3, // Centrado vertical mejorado
                     row.values[col_idx],
                     text_color,
                 ));