fix(ai): honor OpenAI Responses developer role compat

closes #5456

packages/coding-agent/CHANGELOG.md

@@ -10,6 +10,7 @@
 
 ### Fixed
 
+- Fixed `models.json` schema support for OpenAI Responses `compat.supportsDeveloperRole` ([#5456](https://github.com/earendil-works/pi/issues/5456)).
 - Fixed tmux setup documentation to require tmux 3.5 for `extended-keys-format csi-u` and document the tmux 3.2-3.4 fallback ([#5432](https://github.com/earendil-works/pi/issues/5432)).
 - Fixed built-in tool expand hints to style closing parentheses consistently ([#5359](https://github.com/earendil-works/pi/issues/5359)).
 

packages/coding-agent/src/core/model-registry.ts

@@ -127,6 +127,7 @@ const OpenAICompletionsCompatSchema = Type.Object({
 });
 
 const OpenAIResponsesCompatSchema = Type.Object({
+	supportsDeveloperRole: Type.Optional(Type.Boolean()),
 	sendSessionIdHeader: Type.Optional(Type.Boolean()),
 	supportsLongCacheRetention: Type.Optional(Type.Boolean()),
 });