feat(welcome): 站点外观 - 合并欢迎页开放开关与入口分包修复

# Conflicts:
#	docs/content/docs/progress/pending-test.mdx

backend/internal/app/feature_availability_test.go

@@ -5,6 +5,7 @@ import (
 	"testing"
 
 	"infinite-canvas/backend/internal/model"
+	"infinite-canvas/backend/internal/platform"
 	"infinite-canvas/backend/internal/protocol"
 	"infinite-canvas/backend/internal/repository"
 
@@ -19,6 +20,9 @@ func TestFeatureAvailabilityDefaultsToDisableFrontendModels(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
+	if !setting.WelcomeEnabled {
+		t.Fatal("welcome should be enabled by default")
+	}
 	if setting.Configured || !setting.ShortDramaEnabled || !setting.TaskCenterEnabled || !setting.CreditsEnabled || !setting.CustomChannelsEnabled || setting.FrontendModelsEnabled || !setting.PluginCenterEnabled || !setting.SystemPluginsVisibleToUsers {
 		t.Fatalf("FeatureAvailability() = %#v", setting)
 	}
@@ -38,6 +42,28 @@ func TestFeatureAvailabilityLegacySettingKeepsCustomChannelsEnabled(t *testing.T
 	if setting.ShortDramaEnabled || !setting.CustomChannelsEnabled || setting.FrontendModelsEnabled || !setting.PluginCenterEnabled || !setting.SystemPluginsVisibleToUsers {
 		t.Fatalf("FeatureAvailability() = %#v", setting)
 	}
+	if !setting.WelcomeEnabled {
+		t.Fatal("existing settings without welcomeEnabled should keep welcome enabled")
+	}
+}
+
+func TestWelcomeAvailabilityCanBeDisabledAndReenabled(t *testing.T) {
+	svc, _ := newFeatureAvailabilityTestService(t)
+	actor := &model.User{ID: "admin-welcome", Role: model.UserRoleAdmin}
+	for _, enabled := range []bool{false, true} {
+		value := platform.DefaultFeatureAvailability()
+		value.WelcomeEnabled = enabled
+		if _, err := svc.UpdateFeatureAvailability(actor, value); err != nil {
+			t.Fatal(err)
+		}
+		setting, err := svc.FeatureAvailability()
+		if err != nil {
+			t.Fatal(err)
+		}
+		if setting.WelcomeEnabled != enabled {
+			t.Fatalf("welcomeEnabled = %v, want %v", setting.WelcomeEnabled, enabled)
+		}
+	}
 }
 
 func TestUpdateFeatureAvailabilityPersistsAndAudits(t *testing.T) {

backend/internal/handler/feature_availability.go

@@ -9,6 +9,16 @@ import (
 )
 
 func RegisterFeatureAvailabilityRoutes(r *gin.RouterGroup, svc *service.Service) {
+	r.GET("/public/welcome", func(c *gin.Context) {
+		c.Header("Cache-Control", "no-store")
+		setting, err := svc.FeatureAvailability()
+		if err != nil {
+			failService(c, err)
+			return
+		}
+		ok(c, gin.H{"welcomeEnabled": setting.WelcomeEnabled})
+	})
+
 	r.GET("/features", func(c *gin.Context) {
 		if _, err := currentUser(c, svc); err != nil {
 			failService(c, err)

backend/internal/handler/openapi.yaml

@@ -24,6 +24,16 @@ tags:
   - name: agent
   - name: admin
 paths:
+  /public/welcome:
+    get:
+      tags: [meta]
+      security: []
+      summary: 读取欢迎页开放状态
+      responses:
+        "200":
+          description: 信封 data 仅包含 welcomeEnabled 布尔值，默认 true；Cache-Control 为 no-store
+        "500":
+          description: 配置读取失败
   /agent/capabilities:
     get:
       tags: [agent]

backend/internal/handler/welcome_routes_test.go

@@ -0,0 +1,56 @@
+package handler
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"infinite-canvas/backend/internal/model"
+	"infinite-canvas/backend/internal/repository"
+	"infinite-canvas/backend/internal/service"
+
+	"github.com/gin-gonic/gin"
+	"gorm.io/driver/sqlite"
+	"gorm.io/gorm"
+)
+
+func TestWelcomeAvailabilityPublicRoute(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	db, err := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	sqlDB, err := db.DB()
+	if err != nil {
+		t.Fatal(err)
+	}
+	sqlDB.SetMaxOpenConns(1)
+	t.Cleanup(func() { _ = sqlDB.Close() })
+	if err := db.AutoMigrate(&model.SystemSetting{}); err != nil {
+		t.Fatal(err)
+	}
+	router := gin.New()
+	RegisterFeatureAvailabilityRoutes(router.Group("/api"), service.New(repository.New(db), t.TempDir()))
+	for _, enabled := range []bool{true, false, true} {
+		payload, _ := json.Marshal(map[string]bool{"welcomeEnabled": enabled})
+		if err := db.Save(&model.SystemSetting{Key: "feature_availability", ValueJSON: string(payload)}).Error; err != nil {
+			t.Fatal(err)
+		}
+		response := httptest.NewRecorder()
+		router.ServeHTTP(response, httptest.NewRequest(http.MethodGet, "/api/public/welcome", nil))
+		if response.Code != http.StatusOK || response.Header().Get("Cache-Control") != "no-store" {
+			t.Fatalf("unexpected public response: %d %s", response.Code, response.Body.String())
+		}
+		var body struct {
+			Code int             `json:"code"`
+			Data map[string]bool `json:"data"`
+		}
+		if err := json.Unmarshal(response.Body.Bytes(), &body); err != nil {
+			t.Fatal(err)
+		}
+		if body.Code != 0 || len(body.Data) != 1 || body.Data["welcomeEnabled"] != enabled {
+			t.Fatalf("unexpected public payload: %s", response.Body.String())
+		}
+	}
+}

backend/internal/platform/feature_availability.go

@@ -26,6 +26,7 @@ const (
 )
 
 type FeatureAvailability struct {
+	WelcomeEnabled               bool `json:"welcomeEnabled"`
 	ShortDramaEnabled            bool `json:"shortDramaEnabled"`
 	TaskCenterEnabled            bool `json:"taskCenterEnabled"`
 	CreditsEnabled               bool `json:"creditsEnabled"`
@@ -46,6 +47,7 @@ type PublicFeatureAvailability struct {
 func DefaultFeatureAvailability() FeatureAvailability {
 	// 缺少配置代表尚未由运维接管；前台模型需要明确配置后才开放。
 	return FeatureAvailability{
+		WelcomeEnabled:               true,
 		ShortDramaEnabled:            true,
 		TaskCenterEnabled:            true,
 		CreditsEnabled:               true,