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>

backend/internal/server/server.go

@@ -6,6 +6,8 @@ import (
 
 	"github.com/food-ai/backend/internal/auth"
 	"github.com/food-ai/backend/internal/middleware"
+	"github.com/food-ai/backend/internal/recommendation"
+	"github.com/food-ai/backend/internal/savedrecipe"
 	"github.com/food-ai/backend/internal/user"
 	"github.com/go-chi/chi/v5"
 	"github.com/jackc/pgx/v5/pgxpool"
@@ -15,6 +17,8 @@ func NewRouter(
 	pool *pgxpool.Pool,
 	authHandler *auth.Handler,
 	userHandler *user.Handler,
+	recommendationHandler *recommendation.Handler,
+	savedRecipeHandler *savedrecipe.Handler,
 	authMiddleware func(http.Handler) http.Handler,
 	allowedOrigins []string,
 ) *chi.Mux {
@@ -37,8 +41,18 @@ func NewRouter(
 	// Protected
 	r.Group(func(r chi.Router) {
 		r.Use(authMiddleware)
+
 		r.Get("/profile", userHandler.Get)
 		r.Put("/profile", userHandler.Update)
+
+		r.Get("/recommendations", recommendationHandler.GetRecommendations)
+
+		r.Route("/saved-recipes", func(r chi.Router) {
+			r.Post("/", savedRecipeHandler.Save)
+			r.Get("/", savedRecipeHandler.List)
+			r.Get("/{id}", savedRecipeHandler.GetByID)
+			r.Delete("/{id}", savedRecipeHandler.Delete)
+		})
 	})
 
 	return r