Resolves conflict in main_menu.gd's play button: kept this branch's real
world_list.tscn transition over main's stale TODO placeholder (main's
version predates this fix; nothing else has touched the play button
since). Brings in PR #37's /auth/refresh endpoint and its tests cleanly,
no other conflicts.
- main_menu.gd: Play button now navigates to world_list.tscn
- world_list.gd: fix invalid theme_override_constants property-path syntax
(use add_theme_constant_override), fix @onready node paths missing
/HeaderHBox/, cast Variant dict values to String to avoid type-inference
errors when cards actually render
- world_list.tscn: wire up Back/Refresh button signal connections (scene
had zero [connection] blocks, buttons were dead)
- backend: fix real bug where World.visibility enum sent member names
("PUBLIC") to Postgres instead of lowercase values, breaking both GET
and POST /api/worlds/ for any real query
- backend: fix WorldResponse.created_at typed as str instead of datetime,
causing a second 500 on GET once the enum bug was fixed
- add smoke_test_world_list.gd: headless scene-level smoke test that
registers a user, instantiates the real scene, and confirms world cards
render from live backend data (not just an API-level check)