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_en.g.dart

@@ -192,6 +192,12 @@ class Translations$editVariety$en {
 
 	/// en: 'Notes'
 	String get notes => 'Notes';
+
+	/// en: 'Species (from catalog)'
+	String get species => 'Species (from catalog)';
+
+	/// en: 'Search a species…'
+	String get speciesHint => 'Search a species…';
 }
 
 // Path: addLot
@@ -313,6 +319,8 @@ extension on Translations {
 			'editVariety.name' => 'Name',
 			'editVariety.category' => 'Category',
 			'editVariety.notes' => 'Notes',
+			'editVariety.species' => 'Species (from catalog)',
+			'editVariety.speciesHint' => 'Search a species…',
 			'addLot.title' => 'Add lot',
 			'addLot.year' => 'Harvest year',
 			'addLot.quantity' => 'Quantity',