Cryptid Core Co Field Operations

v0.8.0-f — Stage 8f: Expedition Base, Nest, Crystals & Dogwood Forest

Added
- **Expedition Base 001**: the flagship CCC field base. ~72x72 blocks, 7
  buildings (2 lodges, 3 cabins, 2 tents), common area, paths, branded
  signage, supply chests; the leader's lodge holds a Torn Recipe Page,
  spyglass, emeralds, and labradorite. Rarest structure in the mod
  (1 in 256 chunks, salt 88110207). Forests, taigas, all cryptid biomes.
- **XL structure system**: buildings wider than the worldgen write window
  now generate via deterministic per-chunk replay (seeded rng, zero
  heightmap reads, chunk-clipped writes). Standard buildings unchanged.
- **Bigfoot Nest**: log-and-moss ground nest with fur tufts, 25% claimed
  crystal shard, 30% resident family (adult pair + kid, homed to the
  nest). ~1 in 225 chunks, salt 88110208.
- **Crystal crafting**: Crystal Tuning Fork (hums when a Bigfoot is
  within 48 blocks, pitch rises as it closes), Black Tourmaline Ward
  Charm (carried: adult Bigfoots keep 16 blocks instead of 10), Crystal-
  Bound Field Journal (journal + labradorite), five crystal lanterns
  (light 11-15 by crystal), five crystal display stands.
- **Dogwood Forest biome**: white-canopy forest carved from birch donors
  via TerraBlender. Dogwood-dominant trees, strawberries, mulberries,
  Sika deer, natural White Bigfoot spawns, zero hostiles. Weir, boat
  house, and campsite can generate here.

Changed
- Bigfoot AI: new ward-charm avoid goal beside the Stage 4 beam-lit goal.
- Deer variant dispatch: Dogwood Forest resolves to Sika.
- minecraft:is_forest / is_overworld tags include Dogwood Forest.