Promote base2-gpt-5 to base2-max #4232

Job	Run time
build-and-check	3m 5s
test-cli	1m 15s
test-.agents	54s
test-backend	51s
test-packages/agent-runtime	1m 3s
test-common	1m 0s
test-packages/billing	1m 2s
test-packages/internal	56s
test-npm-app	57s
test-integration-npm-app	55s
test-integration-.agents	59s
test-integration-packages/agent-runtime	53s
test-web	54s
test-integration-backend	58s
test-integration-cli	1m 0s
test-integration-common	49s
test-integration-web	54s
test-integration-packages/internal	58s
test-integration-packages/billing	56s
	20m 19s

Provide feedback