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/data/species_catalog.dart

@@ -0,0 +1,30 @@
+import 'dart:convert';
+
+import 'package:flutter/services.dart' show rootBundle;
+
+import 'species_repository.dart';
+
+const _catalogAsset = 'assets/catalog/species.json';
+
+/// Parses the bundled catalog JSON into [SpeciesSeed]s. Kept separate from asset
+/// loading so it is trivially unit-testable without a Flutter binding.
+List<SpeciesSeed> parseSpeciesCatalog(String jsonString) {
+  final data = jsonDecode(jsonString) as Map<String, dynamic>;
+  final entries = (data['species'] as List).cast<Map<String, dynamic>>();
+  return entries.map((e) {
+    final common = (e['common'] as Map<String, dynamic>? ?? const {}).map(
+      (lang, names) => MapEntry(lang, (names as List).cast<String>()),
+    );
+    return SpeciesSeed(
+      scientificName: e['scientific_name'] as String,
+      family: e['family'] as String?,
+      commonNames: common,
+    );
+  }).toList();
+}
+
+/// Loads and parses the bundled species catalog asset.
+Future<List<SpeciesSeed>> loadBundledSpecies() async {
+  final jsonString = await rootBundle.loadString(_catalogAsset);
+  return parseSpeciesCatalog(jsonString);
+}