feat: async dish recognition (Kafka/Watermill/SSE) + remove Wire + consolidate migrations

Async recognition pipeline:
- POST /ai/recognize-dish → 202 {job_id, queue_position, estimated_seconds}
- GET /ai/jobs/{id}/stream — SSE stream: queued → processing → done/failed
- Kafka topics: ai.recognize.paid (3 partitions) + ai.recognize.free (1 partition)
- 5-worker WorkerPool with priority loop (paid consumers first)
- SSEBroker via PostgreSQL LISTEN/NOTIFY
- Kafka adapter migrated from franz-go to Watermill (watermill-kafka/v2)
- Docker Compose: added Kafka + Zookeeper + kafka-init service
- Flutter: recognition_service.dart uses SSE; home_screen shows live job status

Remove google/wire (archived):
- Deleted wire.go (wireinject spec) and wire_gen.go
- Added cmd/server/init.go — plain Go manual DI, same initApp() logic
- Removed github.com/google/wire from go.mod

Consolidate migrations:
- Merged 001_initial_schema + 002_seed_data + 003_recognition_jobs into single 001_initial_schema.sql
- Deleted 002_seed_data.sql and 003_recognition_jobs.sql

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

backend/cmd/server/init.go

@@ -0,0 +1,108 @@
+package main
+
+import (
+	"github.com/food-ai/backend/internal/adapters/firebase"
+	"github.com/food-ai/backend/internal/domain/auth"
+	"github.com/food-ai/backend/internal/domain/diary"
+	"github.com/food-ai/backend/internal/domain/dish"
+	"github.com/food-ai/backend/internal/domain/home"
+	"github.com/food-ai/backend/internal/domain/ingredient"
+	"github.com/food-ai/backend/internal/domain/menu"
+	"github.com/food-ai/backend/internal/domain/product"
+	"github.com/food-ai/backend/internal/domain/recipe"
+	"github.com/food-ai/backend/internal/domain/recognition"
+	"github.com/food-ai/backend/internal/domain/recommendation"
+	"github.com/food-ai/backend/internal/domain/savedrecipe"
+	"github.com/food-ai/backend/internal/domain/user"
+	"github.com/food-ai/backend/internal/infra/config"
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+func initApp(appConfig *config.Config, pool *pgxpool.Pool) (*App, error) {
+	credentialsFile := newFirebaseCredentialsFile(appConfig)
+	tokenVerifier, firebaseError := firebase.NewAuthOrNoop(credentialsFile)
+	if firebaseError != nil {
+		return nil, firebaseError
+	}
+	userRepository := user.NewRepository(pool)
+	mainJwtSecret := newJWTSecret(appConfig)
+	mainJwtAccessDuration := newJWTAccessDuration(appConfig)
+	mainJwtRefreshDuration := newJWTRefreshDuration(appConfig)
+	jwtManager := newJWTManager(mainJwtSecret, mainJwtAccessDuration, mainJwtRefreshDuration)
+	authService := auth.NewService(tokenVerifier, userRepository, jwtManager)
+	authHandler := auth.NewHandler(authService)
+	userService := user.NewService(userRepository)
+	userHandler := user.NewHandler(userService)
+	mainGeminiAPIKey := newOpenAIAPIKey(appConfig)
+	openaiClient := newOpenAIClient(mainGeminiAPIKey)
+	mainPexelsAPIKey := newPexelsAPIKey(appConfig)
+	pexelsClient := newPexelsClient(mainPexelsAPIKey)
+	productRepository := product.NewRepository(pool)
+	recommendationHandler := recommendation.NewHandler(openaiClient, pexelsClient, userRepository, 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)
+
+	// Kafka producer and consumers
+	kafkaProducer, kafkaProducerError := newKafkaProducer(appConfig)
+	if kafkaProducerError != nil {
+		return nil, kafkaProducerError
+	}
+	paidConsumer, paidConsumerError := newPaidKafkaConsumer(appConfig)
+	if paidConsumerError != nil {
+		return nil, paidConsumerError
+	}
+	freeConsumer, freeConsumerError := newFreeKafkaConsumer(appConfig)
+	if freeConsumerError != nil {
+		return nil, freeConsumerError
+	}
+
+	// Recognition pipeline
+	jobRepository := recognition.NewJobRepository(pool)
+	sseBroker := recognition.NewSSEBroker(pool, jobRepository)
+	workerPool := recognition.NewWorkerPool(jobRepository, openaiClient, dishRepository, paidConsumer, freeConsumer)
+	recognitionHandler := recognition.NewHandler(openaiClient, ingredientRepository, jobRepository, kafkaProducer, sseBroker)
+
+	menuRepository := menu.NewRepository(pool)
+	menuHandler := menu.NewHandler(menuRepository, openaiClient, pexelsClient, userRepository, productRepository, dishRepository)
+	diaryRepository := diary.NewRepository(pool)
+	diaryHandler := diary.NewHandler(diaryRepository, dishRepository, dishRepository)
+	homeHandler := home.NewHandler(pool)
+	dishHandler := dish.NewHandler(dishRepository)
+	recipeRepository := recipe.NewRepository(pool)
+	recipeHandler := recipe.NewHandler(recipeRepository)
+	mainJwtAdapter := newJWTAdapter(jwtManager)
+	authMiddlewareFn := newAuthMiddleware(mainJwtAdapter)
+	mainAllowedOrigins := newAllowedOrigins(appConfig)
+	mainUnitsListHandler := newUnitsListHandler(pool)
+	mainCuisineListHandler := newCuisineListHandler(pool)
+	mainTagListHandler := newTagListHandler(pool)
+	httpHandler := newRouter(
+		pool,
+		authHandler,
+		userHandler,
+		recommendationHandler,
+		savedrecipeHandler,
+		ingredientHandler,
+		productHandler,
+		recognitionHandler,
+		menuHandler,
+		diaryHandler,
+		homeHandler,
+		dishHandler,
+		recipeHandler,
+		authMiddlewareFn,
+		mainAllowedOrigins,
+		mainUnitsListHandler,
+		mainCuisineListHandler,
+		mainTagListHandler,
+	)
+	return &App{
+		handler:    httpHandler,
+		workerPool: workerPool,
+		sseBroker:  sseBroker,
+	}, nil
+}