feat(message_gateway): expose PushRegistry contract

backend/core/contracts/push.go

@@ -0,0 +1,26 @@
+// Copyright 2026 Arctel.net
+// SPDX-License-Identifier: Apache-2.0
+
+// Package contracts defines unified service interfaces and DTOs for cross-plugin communication.
+package contracts
+
+import "context"
+
+type PushNotificationTemplate struct {
+	Title   string
+	Content string
+	Level   string
+	Ext     map[string]any
+}
+
+type PushEventMeta struct {
+	Key             string
+	Name            string
+	Description     string
+	DefaultTemplate PushNotificationTemplate
+}
+
+type PushRegistry interface {
+	RegisterBuiltInEvent(meta PushEventMeta)
+	SyncEvents(ctx context.Context) error
+}

backend/plugins/domain/message_gateway/plugin.go

@@ -231,8 +231,9 @@ func (p *Plugin) Apply(ctx *core.Context) error {
 		return nil
 	})
 
-	// 9. Register built-in domain events
+	// 9. Register built-in domain events and provide PushRegistry
 	service.RegisterCustomEvents()
+	core.Provide[contracts.PushRegistry](ctx, service.PushRegistryAdapter{})
 
 	// 10. Register Settings Schemas
 	ctx.Settings().Register(extpoints.SettingSchema{

backend/plugins/domain/message_gateway/plugin_registry_test.go

@@ -0,0 +1,54 @@
+// Copyright 2026 Arctel.net
+// SPDX-License-Identifier: Apache-2.0
+
+package message_gateway_test
+
+import (
+	"Wavelet/core"
+	"Wavelet/core/contracts"
+	"Wavelet/plugins/domain/message_gateway"
+	"Wavelet/plugins/domain/message_gateway/service"
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestPushRegistry(t *testing.T) {
+	ctx := core.NewContext(context.Background())
+	require.NoError(t, message_gateway.New().Apply(ctx))
+
+	registry, err := core.Inject[contracts.PushRegistry](ctx)
+	require.NoError(t, err)
+	require.NotNil(t, registry)
+
+	const key = "test.push_registry.probe"
+	registry.RegisterBuiltInEvent(contracts.PushEventMeta{
+		Key:         key,
+		Name:        "Push Registry Probe",
+		Description: "observability probe for contracts.PushRegistry",
+		DefaultTemplate: contracts.PushNotificationTemplate{
+			Title:   "Probe Title",
+			Content: "Probe Content",
+			Level:   "INFO",
+			Ext:     map[string]any{"source": "test"},
+		},
+	})
+
+	found := false
+	for _, ev := range service.GetBuiltInEvents() {
+		if ev.Key != key {
+			continue
+		}
+		found = true
+		assert.Equal(t, "Push Registry Probe", ev.Name)
+		assert.Equal(t, "observability probe for contracts.PushRegistry", ev.Description)
+		assert.Equal(t, "Probe Title", ev.DefaultTemplate.Title)
+		assert.Equal(t, "Probe Content", ev.DefaultTemplate.Content)
+		assert.Equal(t, "INFO", ev.DefaultTemplate.Level)
+		assert.Equal(t, map[string]any{"source": "test"}, ev.DefaultTemplate.Ext)
+		break
+	}
+	require.True(t, found, "registered key %q should be visible via GetBuiltInEvents", key)
+}

backend/plugins/domain/message_gateway/service/push.go

@@ -49,6 +49,31 @@ func GetBuiltInEvents() []model.EventMetadata {
 	return out
 }
 
+// PushRegistryAdapter adapts contracts.PushRegistry onto the built-in event store.
+type PushRegistryAdapter struct{}
+
+func (PushRegistryAdapter) RegisterBuiltInEvent(meta contracts.PushEventMeta) {
+	RegisterBuiltInEvent(eventMetadataFromContract(meta))
+}
+
+func (PushRegistryAdapter) SyncEvents(ctx context.Context) error {
+	return SyncEvents(ctx)
+}
+
+func eventMetadataFromContract(meta contracts.PushEventMeta) model.EventMetadata {
+	return model.EventMetadata{
+		Key:         meta.Key,
+		Name:        meta.Name,
+		Description: meta.Description,
+		DefaultTemplate: model.NotificationMessage{
+			Title:   meta.DefaultTemplate.Title,
+			Content: meta.DefaultTemplate.Content,
+			Level:   meta.DefaultTemplate.Level,
+			Ext:     meta.DefaultTemplate.Ext,
+		},
+	}
+}
+
 // SyncBuiltInEvents seeds a database row for every registered built-in event.
 func SyncBuiltInEvents(ctx context.Context) error {
 	for _, meta := range GetBuiltInEvents() {