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/recommendations_screen.dart

@@ -0,0 +1,142 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:go_router/go_router.dart';
+
+import '../../shared/models/recipe.dart';
+import 'recipe_provider.dart';
+import 'widgets/recipe_card.dart';
+import 'widgets/skeleton_card.dart';
+
+class RecommendationsScreen extends ConsumerWidget {
+  const RecommendationsScreen({super.key});
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final state = ref.watch(recommendationsProvider);
+
+    return Scaffold(
+      // AppBar is owned by RecipesScreen (tab host), but we add the
+      // refresh action via a floating action button inside this child.
+      body: state.when(
+        loading: () => _SkeletonList(),
+        error: (err, _) => _ErrorView(
+          message: err.toString(),
+          onRetry: () =>
+              ref.read(recommendationsProvider.notifier).load(),
+        ),
+        data: (recipes) => _RecipeList(recipes: recipes),
+      ),
+      floatingActionButton: FloatingActionButton(
+        heroTag: 'refresh_recommendations',
+        tooltip: 'Обновить рекомендации',
+        onPressed: state is AsyncLoading
+            ? null
+            : () => ref.read(recommendationsProvider.notifier).load(),
+        child: state is AsyncLoading
+            ? const SizedBox(
+                width: 24,
+                height: 24,
+                child: CircularProgressIndicator(strokeWidth: 2),
+              )
+            : const Icon(Icons.refresh),
+      ),
+    );
+  }
+}
+
+// ---------------------------------------------------------------------------
+// Skeleton list — shown while AI is generating recipes
+// ---------------------------------------------------------------------------
+
+class _SkeletonList extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) {
+    return ListView.separated(
+      padding: const EdgeInsets.all(16),
+      itemCount: 3,
+      separatorBuilder: (_, __) => const SizedBox(height: 12),
+      itemBuilder: (_, __) => const SkeletonCard(),
+    );
+  }
+}
+
+// ---------------------------------------------------------------------------
+// Loaded recipe list
+// ---------------------------------------------------------------------------
+
+class _RecipeList extends StatelessWidget {
+  final List<Recipe> recipes;
+
+  const _RecipeList({required this.recipes});
+
+  @override
+  Widget build(BuildContext context) {
+    if (recipes.isEmpty) {
+      return const Center(
+        child: Text('Нет рекомендаций. Нажмите ↻ чтобы получить рецепты.'),
+      );
+    }
+
+    return ListView.separated(
+      padding: const EdgeInsets.fromLTRB(16, 16, 16, 88), // room for FAB
+      itemCount: recipes.length,
+      separatorBuilder: (_, __) => const SizedBox(height: 12),
+      itemBuilder: (context, index) {
+        final recipe = recipes[index];
+        return RecipeCard(
+          recipe: recipe,
+          onTap: () => context.push(
+            '/recipe-detail',
+            extra: recipe,
+          ),
+        );
+      },
+    );
+  }
+}
+
+// ---------------------------------------------------------------------------
+// Error view
+// ---------------------------------------------------------------------------
+
+class _ErrorView extends StatelessWidget {
+  final String message;
+  final VoidCallback onRetry;
+
+  const _ErrorView({required this.message, required this.onRetry});
+
+  @override
+  Widget build(BuildContext context) {
+    return Center(
+      child: Padding(
+        padding: const EdgeInsets.all(24),
+        child: Column(
+          mainAxisSize: MainAxisSize.min,
+          children: [
+            const Icon(Icons.error_outline, size: 48, color: Colors.red),
+            const SizedBox(height: 12),
+            const Text(
+              'Не удалось получить рецепты',
+              style: TextStyle(fontSize: 16, fontWeight: FontWeight.bold),
+              textAlign: TextAlign.center,
+            ),
+            const SizedBox(height: 8),
+            Text(
+              message,
+              style: const TextStyle(color: Colors.grey),
+              textAlign: TextAlign.center,
+              maxLines: 3,
+              overflow: TextOverflow.ellipsis,
+            ),
+            const SizedBox(height: 20),
+            ElevatedButton.icon(
+              onPressed: onRetry,
+              icon: const Icon(Icons.refresh),
+              label: const Text('Попробовать снова'),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}