[codex] fix DeepSeek image attachments #481

Job	Run time
build-freebuff	1m 20s
build-and-smoke-freebuff-windows	2m 57s
e2e-code-edit	57s
e2e-help-command	1m 12s
e2e-ads-behavior	1m 1s
e2e-slash-commands	1m 4s
e2e-agent-startup	2m 15s
e2e-terminal-command	59s
e2e-startup	1m 11s
e2e-version	53s
	13m 49s

Provide feedback