refactor: restructure internal/ into adapters/, infra/, and app layers

- internal/gemini/ → internal/adapters/openai/ (renamed package to openai)
- internal/pexels/ → internal/adapters/pexels/
- internal/config/   → internal/infra/config/
- internal/database/ → internal/infra/database/
- internal/locale/   → internal/infra/locale/
- internal/middleware/ → internal/infra/middleware/
- internal/server/   → internal/infra/server/

All import paths and call sites updated accordingly.

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

backend/internal/infra/server/server.go

@@ -0,0 +1,144 @@
+package server
+
+import (
+	"encoding/json"
+	"net/http"
+
+	"github.com/food-ai/backend/internal/auth"
+	"github.com/food-ai/backend/internal/diary"
+	"github.com/food-ai/backend/internal/dish"
+	"github.com/food-ai/backend/internal/home"
+	"github.com/food-ai/backend/internal/ingredient"
+	"github.com/food-ai/backend/internal/language"
+	"github.com/food-ai/backend/internal/menu"
+	"github.com/food-ai/backend/internal/infra/middleware"
+	"github.com/food-ai/backend/internal/recipe"
+	"github.com/food-ai/backend/internal/product"
+	"github.com/food-ai/backend/internal/recognition"
+	"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"
+)
+
+func NewRouter(
+	pool *pgxpool.Pool,
+	authHandler *auth.Handler,
+	userHandler *user.Handler,
+	recommendationHandler *recommendation.Handler,
+	savedRecipeHandler *savedrecipe.Handler,
+	ingredientHandler *ingredient.Handler,
+	productHandler *product.Handler,
+	recognitionHandler *recognition.Handler,
+	menuHandler *menu.Handler,
+	diaryHandler *diary.Handler,
+	homeHandler *home.Handler,
+	dishHandler *dish.Handler,
+	recipeHandler *recipe.Handler,
+	authMiddleware func(http.Handler) http.Handler,
+	allowedOrigins []string,
+	unitsListHandler http.HandlerFunc,
+	cuisineListHandler http.HandlerFunc,
+	tagListHandler http.HandlerFunc,
+) *chi.Mux {
+	r := chi.NewRouter()
+
+	// Global middleware
+	r.Use(middleware.RequestID)
+	r.Use(middleware.Logging)
+	r.Use(middleware.Recovery)
+	r.Use(middleware.CORS(allowedOrigins))
+	r.Use(middleware.Language)
+
+	// Public
+	r.Get("/health", healthCheck(pool))
+	r.Get("/languages", language.List)
+	r.Get("/units", unitsListHandler)
+	r.Get("/cuisines", cuisineListHandler)
+	r.Get("/tags", tagListHandler)
+	r.Route("/auth", func(r chi.Router) {
+		r.Post("/login", authHandler.Login)
+		r.Post("/refresh", authHandler.Refresh)
+		r.Post("/logout", authHandler.Logout)
+	})
+
+	// Protected
+	r.Group(func(r chi.Router) {
+		r.Use(authMiddleware)
+
+		r.Get("/ingredients/search", ingredientHandler.Search)
+
+		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)
+		})
+
+		r.Route("/products", func(r chi.Router) {
+			r.Get("/", productHandler.List)
+			r.Post("/", productHandler.Create)
+			r.Post("/batch", productHandler.BatchCreate)
+			r.Put("/{id}", productHandler.Update)
+			r.Delete("/{id}", productHandler.Delete)
+		})
+
+		r.Route("/dishes", func(r chi.Router) {
+			r.Get("/", dishHandler.List)
+			r.Get("/{id}", dishHandler.GetByID)
+		})
+
+		r.Get("/recipes/{id}", recipeHandler.GetByID)
+
+		r.Route("/menu", func(r chi.Router) {
+			r.Get("/", menuHandler.GetMenu)
+			r.Put("/items/{id}", menuHandler.UpdateMenuItem)
+			r.Delete("/items/{id}", menuHandler.DeleteMenuItem)
+		})
+
+		r.Route("/shopping-list", func(r chi.Router) {
+			r.Get("/", menuHandler.GetShoppingList)
+			r.Post("/generate", menuHandler.GenerateShoppingList)
+			r.Patch("/items/{index}/check", menuHandler.ToggleShoppingItem)
+		})
+
+		r.Route("/diary", func(r chi.Router) {
+			r.Get("/", diaryHandler.GetByDate)
+			r.Post("/", diaryHandler.Create)
+			r.Delete("/{id}", diaryHandler.Delete)
+		})
+
+		r.Get("/home/summary", homeHandler.GetSummary)
+
+		r.Route("/ai", func(r chi.Router) {
+			r.Post("/recognize-receipt", recognitionHandler.RecognizeReceipt)
+			r.Post("/recognize-products", recognitionHandler.RecognizeProducts)
+			r.Post("/recognize-dish", recognitionHandler.RecognizeDish)
+			r.Post("/generate-menu", menuHandler.GenerateMenu)
+		})
+	})
+
+	return r
+}
+
+func healthCheck(pool *pgxpool.Pool) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		dbStatus := "connected"
+		if err := pool.Ping(r.Context()); err != nil {
+			dbStatus = "disconnected"
+		}
+
+		w.Header().Set("Content-Type", "application/json")
+		_ = json.NewEncoder(w).Encode(map[string]string{
+			"status":  "ok",
+			"version": "0.1.0",
+			"db":      dbStatus,
+		})
+	}
+}