rename `SendMessagesRequestContext.id` to `chatId` #29

Job	Run time
test node 22	44s
demo demo/vercel/react/use-client-transport	1m 33s
test node 20	48s
test-integration node 24	1m 6s
check	53s
build	38s
test node 24	38s
test-integration node 22	1m 10s
test-integration node 20	1m 7s
demo demo/vercel/react/use-chat	1m 27s
	10m 4s

Provide feedback