feat: implement Iteration 1 — AI recipe recommendations

Backend:
- Add Groq LLM client (llama-3.3-70b) for recipe generation with JSON
  retry strategy (retries only on parse errors, not API errors)
- Add Pexels client for parallel photo search per recipe
- Add saved_recipes table (migration 004) with JSONB fields
- Add GET /recommendations endpoint (profile-aware prompt building)
- Add POST/GET/GET{id}/DELETE /saved-recipes CRUD endpoints
- Wire gemini, pexels, recommendation, savedrecipe packages in main.go

Flutter:
- Add Recipe, SavedRecipe models with json_serializable
- Add RecipeService (getRecommendations, getSavedRecipes, save, delete)
- Add RecommendationsNotifier and SavedRecipesNotifier (Riverpod)
- Add RecommendationsScreen with skeleton loading and refresh FAB
- Add RecipeDetailScreen (SliverAppBar, nutrition tooltip, steps with timer)
- Add SavedRecipesScreen with Dismissible swipe-to-delete and empty state
- Update RecipesScreen to TabBar (Recommendations / Saved)
- Add /recipe-detail route outside ShellRoute (no bottom nav)
- Extend ApiClient with getList() and deleteVoid()

Project:
- Add CLAUDE.md with English-only rule for comments and commit messages

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

client/lib/features/recipes/recipe_service.dart

@@ -0,0 +1,36 @@
+import '../../core/api/api_client.dart';
+import '../../shared/models/recipe.dart';
+import '../../shared/models/saved_recipe.dart';
+
+class RecipeService {
+  final ApiClient _apiClient;
+
+  RecipeService(this._apiClient);
+
+  Future<List<Recipe>> getRecommendations({int count = 5}) async {
+    final data = await _apiClient.getList(
+      '/recommendations',
+      params: {'count': '$count'},
+    );
+    return data
+        .map((e) => Recipe.fromJson(e as Map<String, dynamic>))
+        .toList();
+  }
+
+  Future<List<SavedRecipe>> getSavedRecipes() async {
+    final data = await _apiClient.getList('/saved-recipes');
+    return data
+        .map((e) => SavedRecipe.fromJson(e as Map<String, dynamic>))
+        .toList();
+  }
+
+  Future<SavedRecipe> saveRecipe(Recipe recipe) async {
+    final body = recipe.toJson()..['source'] = 'ai';
+    final response = await _apiClient.post('/saved-recipes', data: body);
+    return SavedRecipe.fromJson(response);
+  }
+
+  Future<void> deleteSavedRecipe(String id) async {
+    await _apiClient.deleteVoid('/saved-recipes/$id');
+  }
+}