Phase 4 play-test fixes: deep caves, fuller cave spawns, strays, shared loot

From Adrian's play-test (2026-10-30):
- The Deep Dark no longer fills the deepslate layer: world/biomes.json
  splits it by temperature (Deep Dark under cold and temperate land,
  basalt deltas under the hottest, ordinary caves between); at y -52 it
  drops from 30 % to 14 % of the land, basalt 7 %.
- Cave zones fill up to their targets with lines whose primary type fits
  the cave; top stages spawn up to the band's top (Deep Dark Lv 60, Basalt
  70); no time-of-day conditions underground.
- Wild Pokemon more than 10 levels above the band of the zone they
  wander into despawn (zone/Wanderers.kt).
- Loot is shared: all players in one scoreboard team, Lootr team_loot.
- Basalt ore nodes reach the deep basalt.
Self-tests strays_despawn and loot_is_shared; the catching rules from the
previous commit are now tested too. Template rebuilt (world check passed),
island quick check passed (36 self-tests and the restart test).
Shoulder Pokemon noted for Phase 5.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/checklists/phase-4.md

@@ -34,6 +34,23 @@ In game:
 - [ ] Beat a guardian: the chat lists what it unlocked at your base.
 - [ ] Try to place a Power Block in survival before the Jungle guardian: it's refused with a message; after `/cobblesurvival progress grant <you> jungle` it places, and an Electric-type Pokémon inside makes energy (the block's screen and Jade show it).
 
+## From the play-test (2026-10-30)
+
+Built after Adrian's reports; the new template is the save "Cobblemon Survival Island (Phase 4b)".
+
+- **Catching:** the catch rate falls with the level gap to your strongest party Pokémon (2 % at +20 levels); a failed catch makes the Pokémon attack you; a wild Pokémon above your strongest attacks you on sight (16 blocks). Automated: `catch_rate_falls_with_level_gap`, `failed_catch_enrages`, `strong_wild_pokemon_hunt_weak_trainers`, `wild_pokemon_ignore_stronger_trainers`.
+- **Deep caves:** the Deep Dark only lies under cold and temperate land now; under the hottest land the deep layer is basalt deltas (Basalt Furnace, Lv 55–70); elsewhere ordinary caves. Cave zones got fuller tables (16–21 lines, fitting types) and reach the top of their bands (Deep Dark Lv 60, Basalt Lv 70).
+- **Strays** far above the band of the zone they wander into despawn (`strays_despawn`).
+- **Loot is shared** by all players (`loot_is_shared`). Gilded chests are rolled once and don't refill.
+- **Bee nests** no longer spam their sound.
+
+In game:
+
+- [ ] Throw a ball at a wild Pokémon 20+ levels above your strongest: it almost never sticks; when it breaks out, the Pokémon attacks.
+- [ ] Walk up to a wild Pokémon above your strongest party member: it comes for you. With a stronger team, it leaves you alone (or flees).
+- [ ] Fly through the deepslate layer in spectator mode: sculk only in places, basalt under the hot south-east, plain caves elsewhere; Deep Dark Pokémon up to Lv 60, basalt ones up to Lv 70.
+- [ ] Empty a loot chest, then open it with a second player (or after relogging as another account): it's empty for them too.
+
 ## Ask Adrian: approve Phase 4 before Phase 5
 
 The roadmap's done-when holds (every ore tier in exactly one zone, veins regrow after restart and unload, every Pokémon-sourced recipe input has a source), and base jobs and power are in, gated. Remaining placeholders: the skill stages and the Power Block gate (`docs/balance.md`).