fix(tests): update test payloads to match current *Params model schema

All *Params models require an `agent: Agent` field and SendEventParams
uses `event` (not `message`), SendMessageParams uses `content` (not
`message`). Test fixtures were written against an older schema and
have been failing since the repo was initialized.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: scale-ballen

src/agentex/lib/sdk/fastacp/tests/test_base_acp_server.py

@@ -126,11 +126,20 @@ async def mock_handler(params):
             "jsonrpc": "2.0",
             "method": "event/send",
             "params": {
-                "task": {"id": "test-task", "agent_id": "test-agent", "status": "RUNNING"},
-                "message": {
-                    "type": "text",
-                    "author": "user",
-                    "content": "test message",
+                "agent": {
+                    "id": "test-agent-456",
+                    "name": "test-agent",
+                    "description": "test agent",
+                    "acp_type": "sync",
+                    "created_at": "2023-01-01T00:00:00Z",
+                    "updated_at": "2023-01-01T00:00:00Z",
+                },
+                "task": {"id": "test-task"},
+                "event": {
+                    "id": "evt-1",
+                    "agent_id": "test-agent-456",
+                    "sequence_id": 1,
+                    "task_id": "test-task",
                 },
             },
             "id": "test-1",
@@ -218,11 +227,20 @@ async def mock_handler(params):
             "jsonrpc": "2.0",
             "method": "event/send",
             "params": {
-                "task": {"id": "test-task", "agent_id": "test-agent", "status": "RUNNING"},
-                "message": {
-                    "type": "text",
-                    "author": "user",
-                    "content": "test message",
+                "agent": {
+                    "id": "test-agent-456",
+                    "name": "test-agent",
+                    "description": "test agent",
+                    "acp_type": "sync",
+                    "created_at": "2023-01-01T00:00:00Z",
+                    "updated_at": "2023-01-01T00:00:00Z",
+                },
+                "task": {"id": "test-task"},
+                "event": {
+                    "id": "evt-1",
+                    "agent_id": "test-agent-456",
+                    "sequence_id": 1,
+                    "task_id": "test-task",
                 },
             },
             # No ID = notification
@@ -256,7 +274,17 @@ async def mock_handler(params):
         request = {
             "jsonrpc": "2.0",
             "method": "task/cancel",
-            "params": {"task_id": "test-task-123"},
+            "params": {
+                "agent": {
+                    "id": "test-agent-456",
+                    "name": "test-agent",
+                    "description": "test agent",
+                    "acp_type": "sync",
+                    "created_at": "2023-01-01T00:00:00Z",
+                    "updated_at": "2023-01-01T00:00:00Z",
+                },
+                "task": {"id": "test-task-123"},
+            },
             "id": "test-request-1",
         }
 
@@ -280,7 +308,7 @@ def test_send_message_synchronous_response(self, base_acp_server):
         async def mock_execute_handler(params):
             return {
                 "task_id": params.task.id,
-                "message_content": params.message.content,
+                "message_content": params.content.content,
                 "status": "executed_synchronously",
                 "custom_data": {"processed": True, "timestamp": "2024-01-01T12:00:00Z"},
             }
@@ -291,8 +319,16 @@ async def mock_execute_handler(params):
             "jsonrpc": "2.0",
             "method": "message/send",
             "params": {
-                "task": {"id": "test-task-123", "agent_id": "test-agent", "status": "RUNNING"},
-                "message": {
+                "agent": {
+                    "id": "test-agent-456",
+                    "name": "test-agent",
+                    "description": "test agent",
+                    "acp_type": "sync",
+                    "created_at": "2023-01-01T00:00:00Z",
+                    "updated_at": "2023-01-01T00:00:00Z",
+                },
+                "task": {"id": "test-task-123"},
+                "content": {
                     "type": "text",
                     "author": "user",
                     "content": "Execute this task please",
@@ -340,7 +376,15 @@ async def mock_init_handler(params):
             "jsonrpc": "2.0",
             "method": "task/create",
             "params": {
-                "task": {"id": "test-task-456", "agent_id": "test-agent", "status": "RUNNING"}
+                "agent": {
+                    "id": "test-agent-456",
+                    "name": "test-agent",
+                    "description": "test agent",
+                    "acp_type": "sync",
+                    "created_at": "2023-01-01T00:00:00Z",
+                    "updated_at": "2023-01-01T00:00:00Z",
+                },
+                "task": {"id": "test-task-456"},
             },
             "id": "test-init-1",
         }
@@ -428,11 +472,20 @@ async def failing_handler(params):
             "jsonrpc": "2.0",
             "method": "event/send",
             "params": {
-                "task": {"id": "test-task", "agent_id": "test-agent", "status": "RUNNING"},
-                "message": {
-                    "type": "text",
-                    "author": "user",
-                    "content": "test message",
+                "agent": {
+                    "id": "test-agent-456",
+                    "name": "test-agent",
+                    "description": "test agent",
+                    "acp_type": "sync",
+                    "created_at": "2023-01-01T00:00:00Z",
+                    "updated_at": "2023-01-01T00:00:00Z",
+                },
+                "task": {"id": "test-task"},
+                "event": {
+                    "id": "evt-1",
+                    "agent_id": "test-agent-456",
+                    "sequence_id": 1,
+                    "task_id": "test-task",
                 },
             },
             "id": "test-1",