✨ feat(vscode): state JSON 新增 handoffAttachmentId/handoffFrom，Issue 透出 assignees

Claude-Session: https://claude.ai/code/session_011cEyL6k351U2BzX1Qmygph

vscode/cli/cmd/spx/main.go

@@ -408,6 +408,8 @@ var knownStateFields = map[string]struct{}{
 	"implementStatus":       {},
 	"color":                 {},
 	"autoReview":            {},
+	"handoffAttachmentId":   {},
+	"handoffFrom":           {},
 }
 
 // parseStateComment returns the parsed map when body is a JSON object carrying

vscode/cli/internal/state/schema.json

@@ -101,6 +101,16 @@
     "autoReview": {
       "type": "boolean",
       "description": "本工单是否启用自动审查（覆盖全局 autoReview 设置）。"
+    },
+    "handoffAttachmentId": {
+      "type": "string",
+      "description": "移交会话包在 Gitea 的附件 id；存在即「待接管」，接管完成后清空。",
+      "minLength": 1
+    },
+    "handoffFrom": {
+      "type": "string",
+      "description": "发起移交的 Gitea login。",
+      "minLength": 1
     }
   }
 }