LRM Structure Distance Fix

v1.0.2:
- Rarity tiers now set a distance instead of a dice roll: sameDistanceByTier in lrm-structure-tiers.json gives each tier its own distance before the same structure can appear again. The weighted draw is gone; an old weightedDraw key is ignored.
- Fixed structures built without a start. Big Globe can compute the same start several times; every decision, refusals included, is now remembered by position and by start chunk, so a recalculation always gets the same answer.
- Fixed decisions taken during the spawn point search being forgotten, and the dimension not being found when Big Globe's world preset does not name it.
- Fixed empty biome lists frozen by bclib: with bclib installed, no structure generated or could be located. The list is now re-resolved and the vanilla biome filter keeps its role.
- Fixed thread-safety crashes under C2ME in Repurposed Structures' piece-count caches and in BetterEnd's lake and mountain pieces.
- Added band grouping (bands, layersOutsideBands) for stacked dimensions, a jigsaw piece limit (lrm-structure-piece-limit.txt, empty by default), terrain margins for Big Globe terrain fades, BetterEnd terrain and building options, a keep-awake for Chunky pregens, and /lrmsdf biomemap.
- All logs and generated files are in English, and repeated log lines are written once unless logging is on. Config keys are now English; the old names are still read and rewritten on the next start.
- Every new feature is off until configured. Existing worlds keep their cache.