fix(openflare): improve SWOfflineDomains validation and snapshot diff logic

internal/apps/openflare/option/openresty_validators.go

@@ -260,7 +260,7 @@ func validateSWOfflineHTML(key, value string) error {
 
 func validateSWOfflineDomains(key, value string) error {
 	var domains []string
-	if err := json.Unmarshal([]byte(value), &domains); err != nil {
+	if err := json.Unmarshal([]byte(value), &domains); err != nil || domains == nil {
 		return fmt.Errorf("%s 必须为 JSON 字符串数组", key)
 	}
 	if len(domains) > maxSWOfflineDomains {

internal/apps/openflare/option/openresty_validators_test.go

@@ -106,6 +106,7 @@ func TestValidateSWOfflineDomains(t *testing.T) {
 		{"single", `["example.com"]`, true},
 		{"multiple", `["example.com","api.example.com"]`, true},
 		{"invalid json", `not-json`, false},
+		{"null", "null", false},
 		{"empty element", `[""]`, false},
 		{"duplicate", `["example.com","example.com"]`, false},
 		{"whitespace dedup", `[" Example.com ","example.com"]`, false},