feat(core): subagents inherit the parent session's model and thinking level (#38)

Co-authored-by: Alice <alice@prismshadow.com>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

packages/core/src/omnimessage/types.ts

@@ -86,7 +86,7 @@ export interface SessionMetaPayload {
   system_prompt: string;
   /** The list of tool definitions this Session exposes to the model (full schema, matching what's sent to the LLM). */
   tools: ToolDefinition[];
-  /** The model's thinking level (from system_config.model.thinking_level; "default" when unconfigured). */
+  /** The Session's effective thinking level (an explicit createSession option — e.g. subagent inheritance — else system_config.model.thinking_level; "default" when unconfigured). */
   thinking_level: string;
   /** Absolute path to the Agent State. */
   agent_state: string;