Clarify changed and deleted files in the file viewer (#2670)

* fix(app): distinguish changed and deleted files

Successful reads now reconcile transient missing events without letting stale
cached data mask a deletion. File notices expose only actions valid for the
current buffer state.

* fix(app): preserve file state ordering

* fix(app): allow retrying file checks

* fix(app): clear unchanged file conflicts

* fix(app): keep file conflict recovery consistent

Own disk observation and read ordering in one model so stale reads and failed subscriptions cannot produce contradictory actions.

* fix(app): allow retrying file preview errors

Preserve daemon read errors and expose retry for initial and non-editable file loads.

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

@@ -1520,7 +1520,9 @@ export const ptBR: TranslationResources = {
         cursor: "Linha {{line}}, coluna {{column}}",
         preview: "Prévia",
         source: "Fonte",
-        unavailableTitle: "Arquivo indisponível no disco",
+        deletedTitle: "Arquivo excluído do disco",
+        checkFailedTitle: "Não foi possível verificar o arquivo no disco",
+        preservedDescription: "A cópia aberta foi preservada.",
         conflictDescription: "O conteúdo local foi preservado. Escolha qual versão manter.",
         overwrite: "Sobrescrever",
         reload: "Recarregar",