Port the four asobi_lua commits that landed after the merge snapshot

[Taure]

The asobi_lua merge (#339) snapshotted asobi_lua at its commit b01c5dc
(asobi_lua#124). Verified by byte-comparing every shared module against
asobi@733cec4:src/lua/.

Four commits landed in asobi_lua after that point and are not here:

asobi_lua commit	PR	What
4b4bf8e	widgrensit/asobi_lua#132	game-declared registration mode via a config.lua global
3354e5e	widgrensit/asobi_lua#133	real-Postgres CT coverage for the game.storage.* write path (asobi_lua_storage_SUITE)
af391ff	widgrensit/asobi_lua#131	atomize spawn-template base_state and zone.spawn override keys
1bc28be	widgrensit/asobi_lua#134	validate game.broadcast event names for immediate script feedback

Spot checks: registration appears 20 times in asobi_lua/src/asobi_lua_config.erl
and 0 times in asobi/src/lua/asobi_lua_config.erl. asobi/test/ has
asobi_storage_SUITE.erl (the Erlang storage path) but no equivalent of
asobi_lua_storage_SUITE.erl (the Lua game.storage.* path, which is what let
#296 through).

The four need porting on top of the post-merge refactors here (#340, #341, #342,
#343 all touched src/lua/), so they are not clean cherry-picks.

Why this is blocking

widgrensit/asobi_lua#135 retires asobi_lua to a Docker alias: it deletes the
duplicated source and rebuilds ghcr.io/widgrensit/asobi_lua from asobi alone.
Merging it before these are ported would drop all four out of the published image.

Port these, cut a release, then bump the asobi tag in asobi_lua/rebar.config
to that release and merge the retirement PR.

There is also in-flight work in asobi_lua on a fix/storage-update-badarg-296
branch touching src/lua/asobi_lua_api.erl and test/asobi_lua_api_tests.erl
that should be reopened here.

[Taure]

Ported in #353. All four verified present on main: asobi_lua#131's atomize_keys(BaseState) in asobi_lua_world, #132's registration handling, #133's asobi_lua_storage_SUITE, and #134's broadcast event-name validation.

#132 was reworked rather than applied: asobi#341 (ADR 0006) had moved the game-config write path into core, so a declared registration posture now lands in script_registration via asobi_game_config, layered under the operator's registration key exactly as modes are. No direct set_env writer was reintroduced.

widgrensit/asobi_lua#135 is unblocked once a release carries this.