feat(species): auto-classify variety species from its label

Infer the catalog species a free-text variety label names ("Maiz de la
abuela" -> Zea mays) and prefill the category from the species family.

- Pure, testable matcher (domain/species_autoclassify.dart): whole-word,
  accent/case-insensitive, Unicode-aware (any script), longest-name-wins,
  ambiguous names left unclassified, light plural fold.
- Quick-add and draft naming auto-link the species when the field is empty
  (non-destructive; an explicit category is kept).
- Edit sheet offers a one-tap suggestion from the typed name.

Tests: matcher unit, repository integration, SpeciesRepository.classifyLabel,
and an edit-sheet widget test.

apps/app_seeds/lib/i18n/es.i18n.json

@@ -190,6 +190,7 @@
     "notes": "Notas",
     "species": "Especie (del catálogo)",
     "speciesHint": "Buscar una especie…",
+    "speciesSuggested": "Sugerida por el nombre",
     "organic": "Ecológica",
     "organicHint": "Cultivada de forma ecológica (eco)"
   },