refactor: migrate DI to Wire, replace startup registries with on-demand DB queries

- Add google/wire; generate wire_gen.go from wire.go injector
- Move all constructor wiring out of main.go into providers.go / wire.go
- Export recognition.IngredientRepository (was unexported, blocked Wire binding)
- Delete units/cuisine/tag registry.go files (global state + unused NameFor helpers)
- Replace List handlers with NewListHandler(pool) using COALESCE SQL queries
- Remove units/cuisine/tag LoadFromDB from server startup; locale.LoadFromDB kept
  (locale.Supported is used by language middleware on every request)

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

backend/cmd/server/wire_gen.go

@@ -0,0 +1,73 @@
+// Code generated by Wire. DO NOT EDIT.
+
+//go:generate go run -mod=mod github.com/google/wire/cmd/wire
+//go:build !wireinject
+// +build !wireinject
+
+package main
+
+import (
+	"github.com/food-ai/backend/internal/auth"
+	"github.com/food-ai/backend/internal/config"
+	"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/menu"
+	"github.com/food-ai/backend/internal/product"
+	"github.com/food-ai/backend/internal/recipe"
+	"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/jackc/pgx/v5/pgxpool"
+	"net/http"
+)
+
+// Injectors from wire.go:
+
+func initRouter(appConfig *config.Config, pool *pgxpool.Pool) (http.Handler, error) {
+	string2 := newFirebaseCredentialsFile(appConfig)
+	tokenVerifier, err := auth.NewFirebaseAuthOrNoop(string2)
+	if err != nil {
+		return nil, err
+	}
+	repository := user.NewRepository(pool)
+	mainJwtSecret := newJWTSecret(appConfig)
+	mainJwtAccessDuration := newJWTAccessDuration(appConfig)
+	mainJwtRefreshDuration := newJWTRefreshDuration(appConfig)
+	jwtManager := newJWTManager(mainJwtSecret, mainJwtAccessDuration, mainJwtRefreshDuration)
+	service := auth.NewService(tokenVerifier, repository, jwtManager)
+	handler := auth.NewHandler(service)
+	userService := user.NewService(repository)
+	userHandler := user.NewHandler(userService)
+	mainGeminiAPIKey := newGeminiAPIKey(appConfig)
+	client := newGeminiClient(mainGeminiAPIKey)
+	mainPexelsAPIKey := newPexelsAPIKey(appConfig)
+	pexelsClient := newPexelsClient(mainPexelsAPIKey)
+	productRepository := product.NewRepository(pool)
+	recommendationHandler := recommendation.NewHandler(client, pexelsClient, repository, productRepository)
+	dishRepository := dish.NewRepository(pool)
+	savedrecipeRepository := savedrecipe.NewRepository(pool, dishRepository)
+	savedrecipeHandler := savedrecipe.NewHandler(savedrecipeRepository)
+	ingredientRepository := ingredient.NewRepository(pool)
+	ingredientHandler := ingredient.NewHandler(ingredientRepository)
+	productHandler := product.NewHandler(productRepository)
+	recognitionHandler := recognition.NewHandler(client, ingredientRepository)
+	menuRepository := menu.NewRepository(pool)
+	menuHandler := menu.NewHandler(menuRepository, client, pexelsClient, repository, productRepository, dishRepository)
+	diaryRepository := diary.NewRepository(pool)
+	diaryHandler := diary.NewHandler(diaryRepository)
+	homeHandler := home.NewHandler(pool)
+	dishHandler := dish.NewHandler(dishRepository)
+	recipeRepository := recipe.NewRepository(pool)
+	recipeHandler := recipe.NewHandler(recipeRepository)
+	mainJwtAdapter := newJWTAdapter(jwtManager)
+	v := newAuthMiddleware(mainJwtAdapter)
+	mainAllowedOrigins := newAllowedOrigins(appConfig)
+	mainUnitsListHandler := newUnitsListHandler(pool)
+	mainCuisineListHandler := newCuisineListHandler(pool)
+	mainTagListHandler := newTagListHandler(pool)
+	httpHandler := newRouter(pool, handler, userHandler, recommendationHandler, savedrecipeHandler, ingredientHandler, productHandler, recognitionHandler, menuHandler, diaryHandler, homeHandler, dishHandler, recipeHandler, v, mainAllowedOrigins, mainUnitsListHandler, mainCuisineListHandler, mainTagListHandler)
+	return httpHandler, nil
+}