feat: message-api for mission via wecomm agent

mission/migrations/0007_missioncategory_payload_processor.py

@@ -0,0 +1,22 @@
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("mission", "0006_mission_and_reply_extra"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="missioncategory",
+            name="payload_processor",
+            field=models.CharField(
+                blank=True,
+                choices=[("structured_description_v1", "结构化描述增强(v1)")],
+                default="",
+                max_length=50,
+                verbose_name="payload 增强器",
+            ),
+        ),
+    ]