0.8.0: JSON plot config + FTB Teams/Chunks integration

Plot system migrated from static Java + KubeJS to a runtime
configurable, FTB-Chunks-integrated system.

* Plot definitions now live in JSON at
  <world>/serverconfig/bnstoolkit/plots.json. Default file written on
  first server start with the three v0.33 plots. Editable in-place
  + reloadable via /bns admin plot reload.

* New static Plot.REGISTRY replaces Plot.ALL. Loaded on ServerStartedEvent.
  Plot.all() returns the current snapshot.

* New FtbBridge.java — compileOnly deps on ftb-teams + ftb-chunks
  (always in the pack). Wraps team lookup, chunk claim/unclaim, and
  the BEFORE_UNCLAIM event.

* /bns admin spawn-init creates the Spawn (cyan) + Plots (gold) server
  teams using configured UUIDs/colors and claims every defined plot
  for the Plots team. Idempotent.

* /bns admin plot define <id> <name> <price> — adds the chunk you're
  standing in to the plot. Re-run with the same id (different chunks)
  to make multi-chunk plots. Auto-claims for the Plots team and
  persists to JSON.

* /bns admin plot list / remove / reload commands.

* /bns plot buy <id> — pays via NumismaticsBridge.spend (cash+bank
  combined), unclaims chunks from Plots team, claims for the buyer's
  personal FTB Teams team. Records ownership in server NBT and the
  player's bnsOwnedPlots list.

* /bns plot release <id> — reverse flow, refunds 50% to bank.

* Plot chunk guard: ClaimedChunkEvent.BEFORE_UNCLAIM subscriber rejects
  any unclaim of a registered plot chunk unless a thread-local
  SYSTEM_UNCLAIMING flag is set (only set during the release/transfer
  flows). Players who try to unclaim via the FTB Chunks UI get a chat
  message redirecting them to /bns plot release.

* KubeJS plots.js retired (.retired suffix kept). All logic now in
  Java; KubeJS no longer participates in plot ownership state.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

gradle.properties

@@ -19,5 +19,5 @@ loader_version_range=[1,)
 mod_id=bnstoolkit
 mod_name=Brass and Sigil Toolkit
 mod_license=All Rights Reserved
-mod_version=0.7.0
+mod_version=0.8.0
 mod_group_id=uk.sijbers.bnstoolkit