fix(#2491): finish todos/done -> todos/completed rename (14 stale refs) + guard (#2626)

* test(#2491): add todos/done rename under-sweep guard

* fix(#2491): finish todos/done -> todos/completed rename (14 stale refs)

* chore(#2491): backfill changeset pr to 2626

* test(#2491): fix lint-legacy-dir-name + allow-test-rule-refs (split legacy token, add issue ref)

docs/pt-BR/ARCHITECTURE.md

@@ -553,7 +553,7 @@ Caminhos equivalentes para outros runtimes:
 │       └── SUMMARY.md
 ├── todos/
 │   ├── pending/            # Ideias capturadas
-│   └── done/               # Todos concluídos
+│   └── completed/          # Todos concluídos
 ├── threads/               # Threads de contexto persistentes (do /gsd-thread)
 ├── seeds/                 # Ideias prospectivas (do /gsd-capture --seed)
 ├── debug/                  # Sessões de depuração ativas

docs/pt-BR/USER-GUIDE.md

@@ -853,7 +853,7 @@ Para desativar a execução paralela completamente: `/gsd-settings` → defina `
   reports/                # Session reports (from /gsd-pause-work --report)
   todos/
     pending/              # Captured ideas awaiting work
-    done/                 # Completed todos
+    completed/             # Completed todos
   debug/                  # Active debug sessions
     resolved/             # Archived debug sessions
   spikes/                 # Feasibility experiments (from /gsd-spike)