feat: allow production provider bootstrap

backend/internal/settings/service.go

@@ -97,7 +97,7 @@ func LoadEnvironment(path string, environment map[string]string) (map[string]str
 	}
 	merged := cloneStrings(environment)
 	for key, value := range file {
-		if _, allowed := fieldIndex[key]; !allowed {
+		if !allowedEnvironmentKey(key) {
 			continue
 		}
 		if _, exists := merged[key]; !exists {
@@ -108,14 +108,25 @@ func LoadEnvironment(path string, environment map[string]string) (map[string]str
 }
 
 func RuntimeSettingKeys() []string {
-	keys := make([]string, 0, len(fieldIndex))
+	keys := make([]string, 0, len(fieldIndex)+len(runtimeOnlyKeys))
 	for key := range fieldIndex {
 		keys = append(keys, key)
 	}
+	for key := range runtimeOnlyKeys {
+		keys = append(keys, key)
+	}
 	sort.Strings(keys)
 	return keys
 }
 
+func allowedEnvironmentKey(key string) bool {
+	if _, allowed := fieldIndex[key]; allowed {
+		return true
+	}
+	_, allowed := runtimeOnlyKeys[key]
+	return allowed
+}
+
 func (s *Service) WithBillingAccountWriter(writer BillingAccountWriter) *Service {
 	s.billing = writer
 	return s
@@ -483,3 +494,9 @@ var fieldIndex = func() map[string]Field {
 	result["VIDEO_GENERATE_ENGINE"] = Field{Key: "VIDEO_GENERATE_ENGINE", Label: "视频生成", Type: "select", DefaultValue: "bailian", Options: []Option{{Label: "Seedance", Value: "seedance"}, {Label: "阿里云百炼 Wan 2.7", Value: "bailian"}}}
 	return result
 }()
+
+// runtimeOnlyKeys are read from the process/settings file by the Go startup
+// loader but are intentionally not exposed as editable settings-panel fields.
+var runtimeOnlyKeys = map[string]struct{}{
+	"ZHINIAN_ALLOW_UNCONFIGURED_PROVIDERS": {},
+}

backend/internal/settings/service_test.go

@@ -100,6 +100,23 @@ func TestServiceGetUsesInjectedEnvironmentWithoutMutatingProcess(t *testing.T) {
 	assertSecretProjection(t, value, "SEEDANCE_API_KEY", true)
 }
 
+func TestLoadEnvironmentAllowsBootstrapRuntimeFlagButIgnoresUnknownKeys(t *testing.T) {
+	path := filepath.Join(t.TempDir(), ".env.local")
+	if err := os.WriteFile(path, []byte("ZHINIAN_ALLOW_UNCONFIGURED_PROVIDERS=true\nUNKNOWN_RUNTIME_FLAG=true\n"), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	values, err := LoadEnvironment(path, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if values["ZHINIAN_ALLOW_UNCONFIGURED_PROVIDERS"] != "true" {
+		t.Fatalf("bootstrap flag = %q", values["ZHINIAN_ALLOW_UNCONFIGURED_PROVIDERS"])
+	}
+	if _, exists := values["UNKNOWN_RUNTIME_FLAG"]; exists {
+		t.Fatal("unknown runtime flag was loaded")
+	}
+}
+
 func TestServiceSynchronizesBillingAccountWithoutRequiringRestart(t *testing.T) {
 	writer := &billingWriterStub{}
 	service := New(filepath.Join(t.TempDir(), ".env.local"), nil, nil).WithBillingAccountWriter(writer)