feat(cloud-agent): 云端 Agent - 完善运行时与资源持久化

backend/internal/app/cloud_agent_model_selection.go

@@ -2,12 +2,104 @@ package app
 
 import (
 	"encoding/json"
+	"fmt"
 	"strings"
+
+	"infinite-canvas/backend/internal/model"
 )
 
 // Keep cross-field validation server-side rather than adding provider-specific
 // root schema combinators. The same contract is advertised by both media tools.
-const cloudAgentModelSelectionDescription = "模型选择必填：将 model_list 返回的一种 selection 展开到顶层参数，必须提供非空 logicalModelId，或同时提供非空 channelId 和 channelModelKey，二者互斥。未使用的选择字段省略或传空字符串，不得传 null 或仅含空白的字符串。缺失、混用或不完整均在提交前拒绝，不会自动选择或切换模型。"
+const cloudAgentModelSelectionDescription = "模型选择：复制 model_list 的 selection 到顶层。完全省略模型字段时，仅使用当前项目对应能力的可用默认模型。显式选择必须提供 logicalModelId，或同时提供 channelId 与 channelModelKey，二者互斥。未使用字段省略或传空字符串，不得传 null/空白；无可用默认、混用或不完整均拒绝，不会随机选模。"
+
+// applyCloudAgentProjectDefaultModel only fills a selection when the Agent did
+// not send any model-selection field at all. An explicitly empty, partial, or
+// null selection remains invalid so a malformed tool call cannot silently turn
+// into a different model.
+func (s *Service) applyCloudAgentProjectDefaultModel(run *model.CloudAgentExecution, state *cloudAgentRuntime, raw string, a *cloudAgentMediaArgs) (bool, error) {
+	if s == nil || s.repo == nil || run == nil || state == nil || a == nil || cloudAgentModelSelectionProvided(raw) {
+		return false, nil
+	}
+	a.Mode = strings.ToLower(strings.TrimSpace(a.Mode))
+	if a.Mode != "image" && a.Mode != "video" || strings.TrimSpace(state.Request.CanvasID) == "" {
+		return false, nil
+	}
+	canvas, err := s.repo.CanvasProjectForUser(run.UserID, state.Request.CanvasID)
+	if err != nil {
+		return false, err
+	}
+	if strings.TrimSpace(canvas.ProjectID) == "" {
+		return false, nil
+	}
+	project, err := s.repo.ProjectForUser(run.UserID, canvas.ProjectID)
+	if err != nil {
+		return false, err
+	}
+	defaultModel := strings.TrimSpace(project.DefaultImageModel)
+	if a.Mode == "video" {
+		defaultModel = strings.TrimSpace(project.DefaultVideoModel)
+	}
+	if defaultModel == "" {
+		return false, nil
+	}
+
+	if channelID, channelModelKey, ok := splitCloudAgentChannelModel(defaultModel); ok {
+		catalog, catalogErr := s.ModelCatalog(nil)
+		if catalogErr != nil {
+			return false, catalogErr
+		}
+		for _, channel := range catalog.Channels {
+			if channel.ID != channelID {
+				continue
+			}
+			for _, channelModel := range channel.Models {
+				if channelModel.ModelKey == channelModelKey && channelModel.Available && normalizeCapability(channelModel.Capability) == a.Mode {
+					a.ChannelID, a.ChannelModelKey = channelID, channelModelKey
+					return true, nil
+				}
+			}
+		}
+		return false, fmt.Errorf("项目默认%s模型不可用或能力不匹配，请在项目设置中重新选择模型", cloudAgentModeLabel(a.Mode))
+	}
+
+	logicalModels, err := s.PublicLogicalModels(nil)
+	if err != nil {
+		return false, err
+	}
+	for _, logicalModel := range logicalModels {
+		if logicalModel.ID == defaultModel && logicalModel.Available && normalizeCapability(logicalModel.Capability) == a.Mode {
+			a.LogicalModelID = defaultModel
+			return true, nil
+		}
+	}
+	return false, fmt.Errorf("项目默认%s模型不可用或能力不匹配，请在项目设置中重新选择模型", cloudAgentModeLabel(a.Mode))
+}
+
+func cloudAgentModelSelectionProvided(raw string) bool {
+	var fields map[string]json.RawMessage
+	if err := json.Unmarshal([]byte(raw), &fields); err != nil || fields == nil {
+		return true
+	}
+	for _, field := range []string{"logicalModelId", "channelId", "channelModelKey"} {
+		if _, ok := fields[field]; ok {
+			return true
+		}
+	}
+	return false
+}
+
+func splitCloudAgentChannelModel(value string) (string, string, bool) {
+	channelID, channelModelKey, ok := strings.Cut(strings.TrimSpace(value), "::")
+	channelID, channelModelKey = strings.TrimSpace(channelID), strings.TrimSpace(channelModelKey)
+	return channelID, channelModelKey, ok && channelID != "" && channelModelKey != ""
+}
+
+func cloudAgentModeLabel(mode string) string {
+	if mode == "video" {
+		return "视频"
+	}
+	return "图片"
+}
 
 func validateCloudAgentModelSelection(raw string, a cloudAgentMediaArgs) error {
 	// Go's JSON decoder accepts null for string fields; the tool contract does
@@ -33,7 +125,7 @@ func validateCloudAgentModelSelection(raw string, a cloudAgentMediaArgs) error {
 	case a.LogicalModelID != "":
 		return nil
 	case a.ChannelID == "" && a.ChannelModelKey == "":
-		return cloudAgentFieldError("logicalModelId", "required", "缺少模型选择：必须复制 model_list 的 logicalModelId 或完整的 channelId/channelModelKey，不会自动选择模型")
+		return cloudAgentFieldError("logicalModelId", "required", "缺少模型选择：请复制 model_list 的 logicalModelId 或完整的 channelId/channelModelKey；若项目未配置当前能力的可用默认模型，不能自动猜测")
 	case a.ChannelID == "":
 		return cloudAgentFieldError("channelId", "required", "系统渠道模型选择不完整：缺少 channelId，请复制 model_list 的完整 selection")
 	case a.ChannelModelKey == "":