chore(deps): update dependency splitpanes to v4 (#834)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

pnpm-lock.yaml

@@ -20,7 +20,7 @@ catalog:
   sass-embedded: ^1.86.0
   serve: ^14.2.4
   shiki: ^3.2.1
-  splitpanes: ^3.2.0
+  splitpanes: ^4.0.3
   typescript: ^5.8.2
   unocss: ^66.0.0
   unplugin-auto-import: ^19.1.2