feat(block1): bundled species catalog + autocomplete link

Add a small curated catalog of Iberian horticultural species and let a variety
be linked to it from the edit sheet.

- assets/catalog/species.json: 14 species with botanical family and ES/EN
  common names (wikidata_qid/gbif_key deferred to the varilla enrichment).
- SpeciesRepository: idempotent seedBundled (is_bundled rows, keyed by
  scientific name) + search by scientific/common name with a locale-best label.
  Seeded on startup from DI.
- VarietyRepository.linkSpecies: sets species_id and prefills category from the
  species' family when empty (never overwrites an existing category).
  VarietyDetail now carries the scientific name.
- Edit sheet gains a live species-search field; the detail view shows the
  scientific name (italic). i18n strings added (ES/EN).

Tests: catalog parse, idempotent seeding, search by scientific/common name,
linkSpecies prefill semantics, and a widget test for the autocomplete → link →
scientific-name-shown flow. Full suite: 32 passing, 0 skipped.

apps/app_seeds/lib/i18n/strings_es.g.dart

@@ -131,6 +131,8 @@ class _Translations$editVariety$es extends Translations$editVariety$en {
 	@override String get name => 'Nombre';
 	@override String get category => 'Categoría';
 	@override String get notes => 'Notas';
+	@override String get species => 'Especie (del catálogo)';
+	@override String get speciesHint => 'Buscar una especie…';
 }
 
 // Path: addLot
@@ -210,6 +212,8 @@ extension on TranslationsEs {
 			'editVariety.name' => 'Nombre',
 			'editVariety.category' => 'Categoría',
 			'editVariety.notes' => 'Notas',
+			'editVariety.species' => 'Especie (del catálogo)',
+			'editVariety.speciesHint' => 'Buscar una especie…',
 			'addLot.title' => 'Añadir lote',
 			'addLot.year' => 'Año de cosecha',
 			'addLot.quantity' => 'Cantidad',