fix(sweep): keep the UI sweep away from real wallet data

The full UI sweep (dev builds only) ran its demo surfaces against the
real profile. Its teardown deleted wallet-{cold,trading,mining,donations,
2023,payroll}.dat from the real datadir, it created zero-filled wallet
files and picker-demo/extra-wallets folders, its demo wallet-index upsert
re-minted the active wallet's scopeId (hiding "w:"-scoped contacts), the
Contacts tab could re-attach legacy-scoped contacts to such a throwaway
id in addressbook.json, and it persisted the demo active wallet file and
Mining pool worker.

- Preflight: a full sweep is refused (toast + log line) while a real
  workflow is in flight: a pending seed_migration_* setting or open
  migrate dialog, a wallet switch, an encryption/import workflow, an
  encrypt/PIN/lock operation, the seed-backup dialog, or a bootstrap.
  The DRAGONX_FULL_SWEEP hook then exits as for an empty catalog.
- Persistence latches: AddressBook (snapshot on the first sweepBegin,
  save/load latched while a demo-contacts surface is shown), WalletIndex
  and Settings (active wallet file, contacts view mode, pool URL/worker)
  for the whole sweep. Settings::sweepEnd() is the last statement of
  clearDemoWalletData and flushes once only if a save was suppressed; a
  quit mid-sweep writes nothing to the profile (the 0700 sandbox, with
  zero-filled demo files only, may stay in the temp dir).
- Scope ids: during a full sweep activeWalletScopeId() returns the
  persisted id or "" and never mints one, so the Contacts tab cannot
  move legacy-scoped contacts to a throwaway id. The only address-book
  write a sweep can still cause is the one-time legacy re-attach to the
  wallet's persisted id, which opening Contacts does anyway.
- Sandbox: demo wallet files and folders go to a fresh random 0700 dir
  under the temp dir (exclusive create, a pre-existing path or symlink
  is refused), removed at sweep end. The teardown that deleted those six
  wallet files is gone.
- Cleanup: the migrate-to-seed state, wizard phase, demo chat
  conversations and a fabricated demo chat identity are reset at sweep
  end; the seed-backup surface always shows the demo phrase and a real
  z_exportmnemonic result is dropped while the sweep runs.
- i18n: one new key (screenshot_sweep_refused) in i18n.cpp and the 8
  language files.

Tests: the address book snapshots only on the first sweepBegin, keeps
addressbook.json byte-identical while latched and restores the real
book; the wallet index keeps wallets.json and the real scope id, also
with the background writer attached; Settings restores the latched
values and flushes once only when a save was suppressed; the sandbox
helper refuses a pre-existing path or symlink and removes only a
prefixed dir, never a symlink's target.

Release note: v2.0.x UI sweeps could delete wallet-{cold,trading,mining,
donations,2023,payroll}.dat from the data directory and re-scope
contacts; this cannot be undone automatically.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

res/lang/es.json

@@ -1666,6 +1666,7 @@
     "screenshot_sweep": "Ejecutar barrido de capturas",
     "screenshot_sweep_desc": "Recorre cada tema en cada pestaña y guarda una captura de pantalla de cada una en subcarpetas por pestaña dentro de la carpeta de capturas del directorio de configuración (sobrescribiendo el barrido anterior). Se ejecuta durante unos segundos.",
     "screenshot_sweep_full": "Barrido completo de la interfaz",
+    "screenshot_sweep_refused": "Barrido completo de la interfaz rechazado; ver registro de depuración",
     "search_icons": "Buscar iconos...",
     "search_placeholder": "Buscar...",
     "sec_changing_passphrase": "Cambiando la frase de contraseña...",