chore: align codebase with bible engineering contracts

- identifier-normalization: use strings.EqualFold in h3c/parser.go
- import-export: CSV now uses UTF-8 BOM and semicolon delimiter
- go-code-style: translate all Russian source strings to English (ADL-007)
- go-background-tasks: add Type, Message, Result fields to Job struct
- go-api: wrap list endpoints in {items, total_count, page, per_page, total_pages}
- module-structure: rename helpers.go → context_sleep.go
- build-version-display: htmlError renders version footer on error pages
- go-logging: migrate all log.Printf calls to log/slog with structured attrs

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

internal/server/handlers_gpu_test.go

@@ -51,17 +51,20 @@ func TestHandleGetSerials_WithGPUs(t *testing.T) {
 	}
 
 	// Parse response
-	var serials []struct {
-		Component    string `json:"component"`
-		Location     string `json:"location,omitempty"`
-		SerialNumber string `json:"serial_number"`
-		Manufacturer string `json:"manufacturer,omitempty"`
-		Category     string `json:"category"`
+	var resp struct {
+		Items []struct {
+			Component    string `json:"component"`
+			Location     string `json:"location,omitempty"`
+			SerialNumber string `json:"serial_number"`
+			Manufacturer string `json:"manufacturer,omitempty"`
+			Category     string `json:"category"`
+		} `json:"items"`
 	}
 
-	if err := json.NewDecoder(w.Body).Decode(&serials); err != nil {
+	if err := json.NewDecoder(w.Body).Decode(&resp); err != nil {
 		t.Fatalf("Failed to decode response: %v", err)
 	}
+	serials := resp.Items
 
 	// Check that we have GPU entries
 	gpuCount := 0
@@ -115,13 +118,16 @@ func TestHandleGetSerials_WithoutGPUSerials(t *testing.T) {
 	srv.handleGetSerials(w, req)
 
 	// Parse response
-	var serials []struct {
-		Category string `json:"category"`
+	var resp struct {
+		Items []struct {
+			Category string `json:"category"`
+		} `json:"items"`
 	}
 
-	if err := json.NewDecoder(w.Body).Decode(&serials); err != nil {
+	if err := json.NewDecoder(w.Body).Decode(&resp); err != nil {
 		t.Fatalf("Failed to decode response: %v", err)
 	}
+	serials := resp.Items
 
 	// Check that GPUs without serial numbers are not included
 	for _, s := range serials {