Add the owner field to tenant-scoped domain contracts

Details (original message):
Add the owner field to tenant-scoped domain contracts (project, conversation, run, artifact, knowledge)

data.go

@@ -99,6 +99,7 @@ type ParserDesc struct {
 // KnowledgeDoc 是检索语料的一条文档（来自 ingest 或插件知识库，带来源标记）。
 type KnowledgeDoc struct {
 	ID       ID        `json:"id"`
+	Owner    ID        `json:"owner,omitempty"`     // 空 = 共享（插件级）知识
 	ProjectID ID       `json:"projectId,omitempty"` // 空 = 插件级知识库
 	Source   string    `json:"source"`              // upload | artifact | plugin:<id>
 	Title    string    `json:"title"`

model.go

@@ -14,8 +14,11 @@ type ID = string
 
 // ---- 项目与会话 ----
 
+// Owner 是租户标识（多租户主线，设计 D5/D16）：空串 = 单租户默认（嵌入式档/
+// 未启用认证时的隐式 owner）。API 层强制 owner 过滤，跨租户访问一律 NotFound。
 type Project struct {
 	ID        ID         `json:"id"`
+	Owner     ID         `json:"owner,omitempty"`
 	Name      string     `json:"name"`
 	CreatedAt time.Time  `json:"createdAt"`
 	UpdatedAt time.Time  `json:"updatedAt"`
@@ -25,6 +28,7 @@ type Project struct {
 type Conversation struct {
 	ID        ID           `json:"id"`
 	ProjectID ID           `json:"projectId"`
+	Owner     ID           `json:"owner,omitempty"` // 冗余自项目，查询过滤用
 	Title     string       `json:"title"`
 	ProfileID ID           `json:"profileId,omitempty"` // 空为默认画像
 	CreatedAt time.Time    `json:"createdAt"`
@@ -157,6 +161,7 @@ type Run struct {
 	ParentRunID    ID           `json:"parentRunId,omitempty"`
 	ConversationID ID           `json:"conversationId"`
 	ProjectID      ID           `json:"projectId"`
+	Owner          ID           `json:"owner,omitempty"` // 冗余自会话
 	Kind           RunKind      `json:"kind"`
 	ProfileID      ID           `json:"profileId,omitempty"`
 	Status         RunStatus    `json:"status"`
@@ -181,6 +186,7 @@ type Usage struct {
 type Artifact struct {
 	ID        ID        `json:"id"`
 	ProjectID ID        `json:"projectId"`
+	Owner     ID        `json:"owner,omitempty"` // 冗余自项目
 	Name      string    `json:"name"`
 	Kind      string    `json:"kind"`
 	MIME      string    `json:"mime,omitempty"`

ts/types.ts

@@ -7,12 +7,12 @@ export type ID = string;
 // ---- 领域模型 ----
 
 export interface Project {
-  id: ID; name: string; createdAt: string; updatedAt: string;
+  id: ID; owner?: ID; name: string; createdAt: string; updatedAt: string;
   settings?: Record<string, unknown>;
 }
 
 export interface Conversation {
-  id: ID; projectId: ID; title: string; profileId?: ID;
+  id: ID; projectId: ID; owner?: ID; title: string; profileId?: ID;
   createdAt: string; updatedAt: string;
 }
 
@@ -52,14 +52,14 @@ export interface Usage {
 }
 
 export interface Run {
-  id: ID; parentRunId?: ID; conversationId: ID; projectId: ID;
+  id: ID; parentRunId?: ID; conversationId: ID; projectId: ID; owner?: ID;
   kind: RunKind; profileId?: ID; status: RunStatus; phase?: RunPhase;
   agentName?: string; createdAt: string; endedAt?: string;
   usage?: Usage; error?: { code: string; message: string };
 }
 
 export interface Artifact {
-  id: ID; projectId: ID; name: string; kind: string; mime?: string;
+  id: ID; projectId: ID; owner?: ID; name: string; kind: string; mime?: string;
   size: number; sourceRun?: ID; createdAt: string; updatedAt: string;
 }
 
@@ -202,7 +202,7 @@ export interface ParsedDocument {
 }
 
 export interface RetrievalHit {
-  doc: { id: ID; projectId?: ID; source: string; title: string; ref?: string; chunk: string; createdAt: string };
+  doc: { id: ID; owner?: ID; projectId?: ID; source: string; title: string; ref?: string; chunk: string; createdAt: string };
   score: number; kind: 'fulltext' | 'vector' | 'plugin';
 }