Expand workspace panel actions and keyboard navigation (#3685)

* fix(app): keep file navigation in place

Retargeting a File tab allocated a new tab identity, causing the tab track to unmount and remount during navigation. Preserve the identity for File-to-File changes while retaining new instances for cross-kind replacements.

* feat(app): expand workspace panel actions

Keep the Command Center aligned with workspace tab and pane primitives. Add explicit panel placement, focused open behavior, keyboard navigation for empty panes, and a Changes pill that toggles the visible Side panel without closing its tab.

packages/app/src/i18n/resources/pt-BR.ts

@@ -64,6 +64,9 @@ export const ptBR: TranslationResources = {
       workspaces: "Espaços de trabalho",
       agents: "Agentes",
       newAgent: "Novo agente",
+      open: "Abrir {{name}}",
+      openInSidePanel: "Abrir {{name}} no painel lateral",
+      openInFocusedPane: "Abrir {{name}} no painel em foco",
       addProject: "Adicionar projeto",
       home: "Início",
       groupByProject: "Agrupar por projeto",