fix: expand openai-codex model catalog to match DEFAULT_CODEX_MODELS (#407)

* fix: expand openai-codex model catalog to match agent DEFAULT_CODEX_MODELS

The _PROVIDER_MODELS["openai-codex"] catalog only listed codex-mini-latest,
so the model dropdown for profiles using openai-codex provider (e.g. CodePath)
showed only that one entry — even when the profile's saved default_model was
gpt-5.4 or another standard Codex model.

Updated to match DEFAULT_CODEX_MODELS from hermes_cli/codex_models.py:
- gpt-5.4
- gpt-5.4-mini
- gpt-5.3-codex
- gpt-5.2-codex
- gpt-5.1-codex-max
- gpt-5.1-codex-mini
- codex-mini-latest (kept, relabeled as 'Codex Mini (latest)')

Also adds 2 regression tests: catalog includes gpt-5.4, display name correct.

* docs: v0.50.28 release — version badge and CHANGELOG

---------

Co-authored-by: Nathan Esquenazi <nesquena@gmail.com>

api/config.py

@@ -466,7 +466,13 @@ _PROVIDER_MODELS = {
         {"id": "o4-mini", "label": "o4-mini"},
     ],
     "openai-codex": [
-        {"id": "codex-mini-latest", "label": "Codex Mini"},
+        {"id": "gpt-5.4", "label": "GPT-5.4"},
+        {"id": "gpt-5.4-mini", "label": "GPT-5.4 Mini"},
+        {"id": "gpt-5.3-codex", "label": "GPT-5.3 Codex"},
+        {"id": "gpt-5.2-codex", "label": "GPT-5.2 Codex"},
+        {"id": "gpt-5.1-codex-max", "label": "GPT-5.1 Codex Max"},
+        {"id": "gpt-5.1-codex-mini", "label": "GPT-5.1 Codex Mini"},
+        {"id": "codex-mini-latest", "label": "Codex Mini (latest)"},
     ],
     "google": [
         {"id": "gemini-2.5-pro", "label": "Gemini 2.5 Pro"},