Pumpkin

Mcxiaocaibug d654e01e25 feat(command): add /locate structure (#2420 )

* feat(command): add /locate structure

Implements /locate structure <name> on top of the existing
find_nearest_structure infrastructure (already used by eyes of ender),
with tab-completion for the known structure sets and vanilla-style
clickable [x, ~, z] teleport coordinates plus horizontal distance in
the success message.

Notes:
- Structure names refer to the generator's structure sets (villages,
  desert_pyramids, ...), optionally prefixed with minecraft:.
- Like the ender-eye path, stronghold (concentric-rings) lookups depend
  on the global structure cache being populated.

Closes #2230

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* refactor(command): derive locate suggestions from generated StructureSet::NAMES

Addresses review feedback: the structure set names are now emitted by
pumpkin-codegen alongside StructureSet::ALL instead of being hard coded
in the locate command.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* feat(command): add /locate biome and /locate poi, use ResourceOrTag arguments

Addresses review feedback on the /locate PR:

- New ResourceOrTagKeyArgument / ResourceOrTagArgument types mirroring
  vanilla's argument pair: both parse `id` or `#tag`, the latter also
  validates against the generated registry/tag data at parse time and
  raises vanilla's argument.resource(_tag).not_found errors.
  /locate structure now uses them instead of StringArgument.
- /locate biome: vanilla-parity spiral search (6400 block radius, 32
  block horizontal / 64 block vertical steps) over the dimension's noise
  biome source via the new find_closest_biome_3d in pumpkin-world,
  including the possibleBiomes short-circuit (walked from the BiomeTree)
  and superflat support. Runs on a blocking thread, reports the 3D
  distance and absolute-y clickable coordinates, and appends the
  concretely found biome for tag searches ("#minecraft:is_forest
  (minecraft:forest)"), all like vanilla.
- /locate poi: searches the world's POI storage within 256 blocks via
  the new PoiStorage::find_closest_matching (chebyshev gather, closest
  by 3D distance, like PoiManager.findClosestWithType), with tag
  support from the generated point_of_interest_type tag data.
- Suggestion matching now also treats ':' as a word separator so that
  e.g. "vil" completes to "minecraft:villages".

Notes / limitations:
- There is no generated structure tag or POI type registry data yet, so
  structure "#tags" resolve to the invalid-structure error and POI ids
  are accepted leniently (unknown ones simply report not-found); only
  nether portal POIs are currently recorded by the server.

Closes #2230

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* refactor(command): run structure search off the async executor, drop panic on join errors

Review follow-ups on the /locate PR:

- /locate structure now runs its search on spawn_blocking like the
  biome search does; scanning up to 100 regions of placement data is
  just as CPU-bound as the biome spiral.
- Blocking-task join errors (panic/cancellation) are mapped to a
  "search failed" command error instead of panicking the command task
  via .expect.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

* chore(command): adapt /locate to upstream API changes

Rebasing onto master picked up three signature changes: WorldGenerator
gained a Custom variant for plugin generators, BIOME_REGISTRY became a
reference, and Level::world_gen is now an ArcSwap.

Plugin generators only expose biomes by generating a whole chunk, so
/locate biome reports no match for them rather than pretending to
search.

* fix(command): report structures /locate can actually find

/locate structure returned the placement grid's candidate chunk without
checking whether a structure grows there. Candidates are only possible
sites: the biome at one can reject every structure in the set, so the
command happily pointed at empty terrain.

Resolve the structure start for random-spread sets instead, over every
structure the set contains, which is what explorer maps already do.
Strongholds keep using the ring cache, whose positions are real and
which the start lookup does not handle.



Co-authored-by: Mcxiaocaibug <Mcxiaocaibug@users.noreply.github.com>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>