feat: let builder use caller or platform llm

agent_builder/skills/agent-quality-review/SKILL.md

@@ -31,7 +31,8 @@ Check these items:
 - The public schema is small and stable. No unbounded command strings, hidden
   prompt fragments, or provider credentials as public inputs.
 - The implementation reads `ctx.llm` for both `CALLER_PROVIDED` and
-  `PLATFORM` LLM provisioning.
+  `PLATFORM` LLM provisioning. `PLATFORM_OR_CALLER_PROVIDED` is acceptable
+  only for trusted platform/meta agents and must also read `ctx.llm`.
 - Generated/user agents should default to
   `llm_provisioning = LLMProvisioning.CALLER_PROVIDED` and
   `Pricing(..., caller_pays_llm=True, ...)`. If the user explicitly wants