Configurable structure toggles for overworld cave generation (#112)

[tastybento]

Fixes #112.

The CaveBlock overworld delegates to vanilla generation, which includes structures like Ancient Cities, Trial Chambers and Strongholds. Some of these fill or unbalance a cave world — the issue shows an Ancient City taking over almost an entire cave area. Bukkit's ChunkGenerator structure flag is all-or-nothing, so this adds per-structure control.

What changed

world.structures config (Map<String, Boolean>)

world:
  structures:
    ancient_city: false
    trial_chambers: false
    mansion: false
    mineshaft: true
    stronghold: true

• Each entry maps a vanilla structure key to whether it may generate.
• Structures not listed generate as normal, so this is non-invasive.
• Defaults disable the big disruptive ones (ancient_city, trial_chambers, mansion) and leave common ones on.
• Only affects the overworld (nether/end don't generate vanilla structures here).

StructureGenerationListener

Cancels AsyncStructureSpawnEvent for any disabled structure in the CaveBlock overworld. The event is async and the handler only reads config + inspects the event (no world access), so it's thread-safe. Key matching tolerates hyphens and casing (e.g. Ancient-City matches ancient_city).

Also

• config.yml documents the new section with the list of accepted structure keys.
• pom.xml — bump build.version to 1.23.0.

Notes

• BentoBox requires both a getter and setter for @ConfigEntry fields; both are provided for the new map.
• Admins can re-enable any structure by setting it to true or removing its entry.

Tests

Added StructureGenerationListenerTest (disabled cancelled, enabled/unlisted allowed, non-CaveBlock world ignored, nether ignored, hyphen/case matching). All 67 tests pass.

🤖 Generated with Claude Code

https://claude.ai/code/session_01KxBgEZz7yHf4eLVzJTw1V5

[sonarqubecloud]

Quality Gate passed

Issues
3 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

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