Add Mailu mailbox skills

a2a.yaml

@@ -1,5 +1,5 @@
 name: mailu-openapi-agent
-version: '1.0'
+version: '1.1'
 entrypoint: agent:MailuOpenapiAgent
 description: Mailu administration agent generated from the live Mailu OpenAPI spec.
 runtime:

agent.py

@@ -86,7 +86,7 @@ class MarkEmailReadInput(BaseModel):
 class MailuOpenapiAgent(A2AAgent):
     name = "mailu-openapi-agent"
     description = "Mailu administration agent generated from the live Mailu OpenAPI spec."
-    version = "1.0"
+    version = "1.1"
     consumer_setup = ConsumerSetup.from_fields(
         ConsumerSetupField.config("OPENAPI_BASE_URL", label="API base URL", description="Override the default API server (https://mail.a2acloud.io/api/v1).", required=False, input_type="url"),
         ConsumerSetupField.secret("AUTHORIZATION", label="Bearer API key", description="Sent as header parameter 'Authorization'. Also used to mint temporary per-user Mailu mailbox tokens for SMTP/IMAP skills.", required=True),