fix: add gpt-5.4 and gpt-5.4-mini to openai-codex curated model list (#7670)

The _PROVIDER_MODELS['openai-codex'] list was missing gpt-5.4 and gpt-5.4-mini,
causing them to not appear in the /model picker for ChatGPT OAuth users.
codex_models.py already had these models in DEFAULT_CODEX_MODELS, but the
curated list that feeds the Telegram/Discord /model picker was never updated.

Reported by @chongdashu

hermes_cli/models.py

@@ -87,6 +87,8 @@ _PROVIDER_MODELS: dict[str, list[str]] = {
         "openai/gpt-5.4-nano",
     ],
     "openai-codex": [
+        "gpt-5.4",
+        "gpt-5.4-mini",
         "gpt-5.3-codex",
         "gpt-5.2-codex",
         "gpt-5.1-codex-mini",