fix: fix menu generation errors and show planned meals on home screen

Backend fixes:
- migration 003: add 'menu' value to recipe_source enum (was causing SQLSTATE 22P02)
- migration 004: rename recipe_products→recipe_ingredients, product_id→ingredient_id (was causing SQLSTATE 42P01)
- dish/repository.go: fix INSERT INTO tags using $1/$1 for two columns → $1/$2 (was causing SQLSTATE 42P08)
- home/handler.go: replace non-existent saved_recipes table with correct joins (recipes→dishes→dish_translations, user_saved_recipes) so today's plan and recommendations load correctly
- reqlog: new slog.Handler wrapper that adds request_id and stack trace to ERROR-level logs
- all handlers: slog.Error→slog.ErrorContext so error logs include request context; writeError includes request_id in response body

Client:
- home_screen.dart: extend home screen to future dates, show planned meals as ghost entries
- l10n: add new localisation keys for home screen date navigation and planned meal UI

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

backend/internal/domain/recognition/handler.go

@@ -125,15 +125,15 @@ func (handler *Handler) RecognizeReceipt(responseWriter http.ResponseWriter, req
 
 	var req imageRequest
 	if decodeError := json.NewDecoder(request.Body).Decode(&req); decodeError != nil || req.ImageBase64 == "" {
-		writeErrorJSON(responseWriter, http.StatusBadRequest, "image_base64 is required")
+		writeErrorJSON(responseWriter, request, http.StatusBadRequest, "image_base64 is required")
 		return
 	}
 
 	lang := locale.FromContext(request.Context())
 	result, recognizeError := handler.recognizer.RecognizeReceipt(request.Context(), req.ImageBase64, req.MimeType, lang)
 	if recognizeError != nil {
-		slog.Error("recognize receipt", "err", recognizeError)
-		writeErrorJSON(responseWriter, http.StatusServiceUnavailable, "recognition failed, please try again")
+		slog.ErrorContext(request.Context(), "recognize receipt", "err", recognizeError)
+		writeErrorJSON(responseWriter, request, http.StatusServiceUnavailable, "recognition failed, please try again")
 		return
 	}
 
@@ -149,7 +149,7 @@ func (handler *Handler) RecognizeReceipt(responseWriter http.ResponseWriter, req
 func (handler *Handler) RecognizeProducts(responseWriter http.ResponseWriter, request *http.Request) {
 	var req imagesRequest
 	if decodeError := json.NewDecoder(request.Body).Decode(&req); decodeError != nil || len(req.Images) == 0 {
-		writeErrorJSON(responseWriter, http.StatusBadRequest, "at least one image is required")
+		writeErrorJSON(responseWriter, request, http.StatusBadRequest, "at least one image is required")
 		return
 	}
 	if len(req.Images) > 3 {
@@ -165,7 +165,7 @@ func (handler *Handler) RecognizeProducts(responseWriter http.ResponseWriter, re
 			defer wg.Done()
 			items, recognizeError := handler.recognizer.RecognizeProducts(request.Context(), imageReq.ImageBase64, imageReq.MimeType, lang)
 			if recognizeError != nil {
-				slog.Warn("recognize products from image", "index", index, "err", recognizeError)
+				slog.WarnContext(request.Context(), "recognize products from image", "index", index, "err", recognizeError)
 				return
 			}
 			allItems[index] = items
@@ -184,7 +184,7 @@ func (handler *Handler) RecognizeProducts(responseWriter http.ResponseWriter, re
 func (handler *Handler) RecognizeDish(responseWriter http.ResponseWriter, request *http.Request) {
 	var req recognizeDishRequest
 	if decodeError := json.NewDecoder(request.Body).Decode(&req); decodeError != nil || req.ImageBase64 == "" {
-		writeErrorJSON(responseWriter, http.StatusBadRequest, "image_base64 is required")
+		writeErrorJSON(responseWriter, request, http.StatusBadRequest, "image_base64 is required")
 		return
 	}
 
@@ -202,8 +202,8 @@ func (handler *Handler) RecognizeDish(responseWriter http.ResponseWriter, reques
 		TargetMealType: req.TargetMealType,
 	}
 	if insertError := handler.jobRepo.InsertJob(request.Context(), job); insertError != nil {
-		slog.Error("insert recognition job", "err", insertError)
-		writeErrorJSON(responseWriter, http.StatusInternalServerError, "failed to create job")
+		slog.ErrorContext(request.Context(), "insert recognition job", "err", insertError)
+		writeErrorJSON(responseWriter, request, http.StatusInternalServerError, "failed to create job")
 		return
 	}
 
@@ -217,8 +217,8 @@ func (handler *Handler) RecognizeDish(responseWriter http.ResponseWriter, reques
 		topic = TopicPaid
 	}
 	if publishError := handler.kafkaProducer.Publish(request.Context(), topic, job.ID); publishError != nil {
-		slog.Error("publish recognition job", "job_id", job.ID, "err", publishError)
-		writeErrorJSON(responseWriter, http.StatusInternalServerError, "failed to enqueue job")
+		slog.ErrorContext(request.Context(), "publish recognition job", "job_id", job.ID, "err", publishError)
+		writeErrorJSON(responseWriter, request, http.StatusInternalServerError, "failed to enqueue job")
 		return
 	}
 
@@ -236,8 +236,8 @@ func (handler *Handler) ListTodayJobs(responseWriter http.ResponseWriter, reques
 
 	summaries, listError := handler.jobRepo.ListTodayUnlinked(request.Context(), userID)
 	if listError != nil {
-		slog.Error("list today unlinked jobs", "err", listError)
-		writeErrorJSON(responseWriter, http.StatusInternalServerError, "failed to list jobs")
+		slog.ErrorContext(request.Context(), "list today unlinked jobs", "err", listError)
+		writeErrorJSON(responseWriter, request, http.StatusInternalServerError, "failed to list jobs")
 		return
 	}
 
@@ -254,8 +254,8 @@ func (handler *Handler) ListAllJobs(responseWriter http.ResponseWriter, request
 
 	summaries, listError := handler.jobRepo.ListAll(request.Context(), userID)
 	if listError != nil {
-		slog.Error("list all jobs", "err", listError)
-		writeErrorJSON(responseWriter, http.StatusInternalServerError, "failed to list jobs")
+		slog.ErrorContext(request.Context(), "list all jobs", "err", listError)
+		writeErrorJSON(responseWriter, request, http.StatusInternalServerError, "failed to list jobs")
 		return
 	}
 
@@ -277,11 +277,11 @@ func (handler *Handler) GetJob(responseWriter http.ResponseWriter, request *http
 
 	job, fetchError := handler.jobRepo.GetJobByID(request.Context(), jobID)
 	if fetchError != nil {
-		writeErrorJSON(responseWriter, http.StatusNotFound, "job not found")
+		writeErrorJSON(responseWriter, request, http.StatusNotFound, "job not found")
 		return
 	}
 	if job.UserID != userID {
-		writeErrorJSON(responseWriter, http.StatusForbidden, "forbidden")
+		writeErrorJSON(responseWriter, request, http.StatusForbidden, "forbidden")
 		return
 	}
 	writeJSON(responseWriter, http.StatusOK, job)
@@ -307,7 +307,7 @@ func (handler *Handler) enrichItems(ctx context.Context, items []ai.RecognizedIt
 
 		catalogProduct, matchError := handler.productRepo.FuzzyMatch(ctx, item.Name)
 		if matchError != nil {
-			slog.Warn("fuzzy match product", "name", item.Name, "err", matchError)
+			slog.WarnContext(ctx, "fuzzy match product", "name", item.Name, "err", matchError)
 		}
 
 		if catalogProduct != nil {
@@ -325,7 +325,7 @@ func (handler *Handler) enrichItems(ctx context.Context, items []ai.RecognizedIt
 		} else {
 			classification, classifyError := handler.recognizer.ClassifyIngredient(ctx, item.Name)
 			if classifyError != nil {
-				slog.Warn("classify unknown product", "name", item.Name, "err", classifyError)
+				slog.WarnContext(ctx, "classify unknown product", "name", item.Name, "err", classifyError)
 			} else {
 				saved := handler.saveClassification(ctx, classification)
 				if saved != nil {
@@ -361,7 +361,7 @@ func (handler *Handler) saveClassification(ctx context.Context, classification *
 
 	saved, upsertError := handler.productRepo.Upsert(ctx, catalogProduct)
 	if upsertError != nil {
-		slog.Warn("upsert classified product", "name", classification.CanonicalName, "err", upsertError)
+		slog.WarnContext(ctx, "upsert classified product", "name", classification.CanonicalName, "err", upsertError)
 		return nil
 	}
 
@@ -417,13 +417,17 @@ func intPtr(n int) *int {
 // ---------------------------------------------------------------------------
 
 type errorResponse struct {
-	Error string `json:"error"`
+	Error     string `json:"error"`
+	RequestID string `json:"request_id,omitempty"`
 }
 
-func writeErrorJSON(responseWriter http.ResponseWriter, status int, msg string) {
+func writeErrorJSON(responseWriter http.ResponseWriter, request *http.Request, status int, msg string) {
 	responseWriter.Header().Set("Content-Type", "application/json")
 	responseWriter.WriteHeader(status)
-	_ = json.NewEncoder(responseWriter).Encode(errorResponse{Error: msg})
+	_ = json.NewEncoder(responseWriter).Encode(errorResponse{
+		Error:     msg,
+		RequestID: middleware.RequestIDFromCtx(request.Context()),
+	})
 }
 
 func writeJSON(responseWriter http.ResponseWriter, status int, value any) {