fix magic mcp session record

[herber]

Note

Medium Risk
This is a potentially breaking API-client change because generated response models and their from_dict mappers stop accepting subspace_session_id/subspace_session_template_id and now expect session_id instead.

Overview
Updates generated Magic MCP session response models for both mt_2025_01_01_dashboard and mt_2026_01_01_magnetar to replace subspace_session_id and subspace_session_template_id with a single session_id field.

All affected get/list outputs (dashboard, management, and non-namespaced resources) and their from_dict mappers are updated to read session_id from API responses, aligning the client models with the new record shape.

^{Reviewed by Cursor Bugbot for commit fd4ee5c. Bugbot is set up for automated code reviews on this repo. Configure here.}