refactor: add to template agent roles

sources/agents/openai_responses_base.toml

@@ -3,16 +3,18 @@ schema_version = 1
 name        = "OpenAI Responses Base"
 description = "OpenAI Responses API request body (/responses). Abstract — extend it and set provider/endpoint/model."
 abstract    = true
-extends     = "Chat Base"
 
 provider_instance = "OpenAI (Responses API)"
 endpoint          = "/responses"
 enable_tools      = true
 tags = ["chat", "openai", "responses", "cloud"]
 
+system_prompt = """{{ agent_role() }}"""
+
 [body]
 max_output_tokens = 8192
 temperature       = 0.7
+stream            = true
 instructions = """{% if existsIn(ctx, "system_prompt") %}{{ tojson(ctx.system_prompt) }}{% endif %}"""
 input = """
 [ {% include "partials/openai_responses_input.jinja" %} ]