OAPI: Add SocketIOTaskUpdate schema

Add the schema for task updates sent via SocketIO.

pkg/api/flamenco-manager.yaml

@@ -1056,6 +1056,26 @@ components:
         "priority": { type: integer, default: 50 }
       required: [id, updated, status, type, priority]
 
+    SocketIOTaskUpdate:
+      type: object
+      description: >
+        Subset of a Task, sent over SocketIO when a task changes.
+        For new tasks, `previous_status` will be excluded.
+      properties:
+        "id":
+          type: string
+          format: uuid
+          description: UUID of the Task
+        "job_id": { type: string, format: uuid }
+        "name": { type: string, description: "Name of the task" }
+        "updated":
+          type: string
+          format: date-time
+          description: Timestamp of last update
+        "status": { $ref: "#/components/schemas/TaskStatus" }
+        "previous_status": { $ref: "#/components/schemas/TaskStatus" }
+      required: [id, job_id, name, updated, status]
+
     SocketIOSubscription:
       type: object
       description: >