fix(app,canvas): 图片档位并集忽略停用线路，重生结果不再继承旧素材绑定

前台分辨率并集只收启用且权重大于 0 的供应线路，避免停用 4K 线路后仍出现不可路由档位。生成回写新媒体时清除旧 assetId，堵住原地重生后「旧素材 + 新资源」配对。

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/internal/app/logical_models.go

@@ -165,11 +165,7 @@ func (s *Service) PublicLogicalModels(intent *ModelRequestIntent) ([]PublicLogic
 
 func publicLogicalModel(cached cachedLogicalModel, available bool) PublicLogicalModel {
 	item := cached.Model
-	routeSpecs := make([]CapabilitySpec, 0, len(cached.Routes))
-	for _, route := range cached.Routes {
-		routeSpecs = append(routeSpecs, route.CapabilitySpec)
-	}
-	productSpec := capabilitySpecWithRoutePresets(cached.ProductSpec, routeSpecs)
+	productSpec := capabilitySpecWithRoutePresets(cached.ProductSpec, enabledLogicalRouteSpecs(cached.Routes))
 	profiles := make([]CapabilitySpec, 0, len(cached.Routes))
 	seen := make(map[string]bool, len(cached.Routes))
 	for _, route := range cached.Routes {
@@ -253,9 +249,22 @@ func normalizeLegacyModelIDs(values []string) []string {
 	return result
 }
 
+func enabledLogicalRouteSpecs(routes []cachedLogicalRoute) []CapabilitySpec {
+	specs := make([]CapabilitySpec, 0, len(routes))
+	for _, route := range routes {
+		if !route.Route.Enabled || route.Route.Weight <= 0 {
+			continue
+		}
+		specs = append(specs, route.CapabilitySpec)
+	}
+	return specs
+}
+
 // capabilitySpecWithRoutePresets repairs old front-model snapshots that stored
 // only `*` for a custom size. The wildcard remains for matching custom values,
 // while route presets are restored for admin and creator-side selectors.
+// Callers must pass only currently enabled routes; disabled or zero-weight
+// routes would otherwise advertise size tiers the public catalog cannot route.
 func capabilitySpecWithRoutePresets(spec CapabilitySpec, routes []CapabilitySpec) CapabilitySpec {
 	result := spec
 	result.Options = make(map[string]OptionConstraint, len(spec.Options))

backend/internal/app/logical_models_test.go

@@ -60,6 +60,37 @@ func TestCapabilitySpecWithRoutePresetsUnionsTiersAcrossRoutes(t *testing.T) {
 	}
 }
 
+func TestEnabledLogicalRouteSpecsOmitsDisabledAndZeroWeightTiers(t *testing.T) {
+	preset := func(size string, tier string, width int, height int) CapabilityImageSizePreset {
+		return CapabilityImageSizePreset{Size: size, Tier: tier, Ratio: "16:9", Width: width, Height: height}
+	}
+	product := CapabilitySpec{
+		Version:    1,
+		Capability: "image",
+		ImageSize:  &CapabilityImageSize{Parameter: "aspect_ratio", Presets: []CapabilityImageSizePreset{preset("1824x1024", "1k", 1824, 1024)}},
+	}
+	routes := []cachedLogicalRoute{
+		{Route: model.LogicalModelRoute{Enabled: true, Weight: 1}, CapabilitySpec: CapabilitySpec{ImageSize: &CapabilityImageSize{Presets: []CapabilityImageSizePreset{preset("2752x1536", "2k", 2752, 1536)}}}},
+		{Route: model.LogicalModelRoute{Enabled: false, Weight: 1}, CapabilitySpec: CapabilitySpec{ImageSize: &CapabilityImageSize{Presets: []CapabilityImageSizePreset{preset("3840x2160", "4k", 3840, 2160)}}}},
+		{Route: model.LogicalModelRoute{Enabled: true, Weight: 0}, CapabilitySpec: CapabilitySpec{ImageSize: &CapabilityImageSize{Presets: []CapabilityImageSizePreset{preset("4096x2304", "4k", 4096, 2304)}}}},
+	}
+
+	got := capabilitySpecWithRoutePresets(product, enabledLogicalRouteSpecs(routes))
+	if got.ImageSize == nil {
+		t.Fatal("imageSize = nil")
+	}
+	tiers := make(map[string]bool, len(got.ImageSize.Presets))
+	for _, item := range got.ImageSize.Presets {
+		tiers[item.Tier] = true
+	}
+	if !tiers["1k"] || !tiers["2k"] {
+		t.Fatalf("expected 1k and 2k from enabled routes: %#v", got.ImageSize.Presets)
+	}
+	if tiers["4k"] {
+		t.Fatalf("disabled and zero-weight 4k routes must not appear in public presets: %#v", got.ImageSize.Presets)
+	}
+}
+
 func TestMatchCapabilityRoutesTextImagesOnlyToDeclaredProfiles(t *testing.T) {
 	plainText := CapabilitySpec{
 		Version:    1,

backend/internal/app/model_router.go

@@ -634,11 +634,7 @@ func (s *Service) loadRouteCatalog() (*routeCatalogSnapshot, error) {
 			}
 			cached.Routes = append(cached.Routes, cachedLogicalRoute{Route: route, CapabilitySpec: capabilitySpec, ChannelModel: channelModel})
 		}
-		routeSpecs := make([]CapabilitySpec, 0, len(cached.Routes))
-		for _, route := range cached.Routes {
-			routeSpecs = append(routeSpecs, route.CapabilitySpec)
-		}
-		productSpec = capabilitySpecWithRoutePresets(productSpec, routeSpecs)
+		productSpec = capabilitySpecWithRoutePresets(productSpec, enabledLogicalRouteSpecs(cached.Routes))
 		defaults, defaultsErr := decodeLogicalDefaults(graph.Revision.DefaultOptionsJSON, productSpec)
 		if defaultsErr != nil {
 			log.Printf("logical model omitted from route catalog id=%s: invalid defaults: %v", item.ID, defaultsErr)