[Bug]: v0.3 JSON-RPC compat adapter returns -32603 for all A2A errors (e.g. TaskNotFound should be -32001) #1368

from starlette.applications import Starlette
from starlette.testclient import TestClient

from a2a.server.agent_execution import AgentExecutor
from a2a.server.request_handlers import DefaultRequestHandler
from a2a.server.routes import create_jsonrpc_routes
from a2a.server.tasks import InMemoryTaskStore
from a2a.types import AgentCapabilities, AgentCard


class NoopExecutor(AgentExecutor):
    async def execute(self, context, event_queue): ...
    async def cancel(self, context, event_queue): ...


card = AgentCard(name='t', description='t', version='1', capabilities=AgentCapabilities())
handler = DefaultRequestHandler(agent_executor=NoopExecutor(), task_store=InMemoryTaskStore(), agent_card=card)
app = Starlette(routes=create_jsonrpc_routes(request_handler=handler, rpc_url='/', enable_v0_3_compat=True))
client = TestClient(app)


def call(method, params, version):
    body = {'jsonrpc': '2.0', 'id': '1', 'method': method, 'params': params}
    return client.post('/', json=body, headers={'A2A-Version': version}).json()['error']['code']


print(call('GetTask', {'id': 'missing'}, '1.0'))    # -32001
print(call('tasks/get', {'id': 'missing'}, '0.3'))  # -32603, expected -32001