Phase 3: Alpha guardians, one per zone, back 5 hours after a defeat

- Companion mod (zone/Guardians.kt): each zone's guardian stands at the
  zone's sample point, appears when a player is within 96 blocks, stays
  within 24 blocks, is uncatchable and half again as big. Beating it in a
  battle gives every player in the battle its drops; it returns after 5
  hours of game time (Adrian: fixed spots, 5 hours). State lives in the
  world save; /cobblesurvival guardians lists it.
- tools/zone_spawns.py writes data/cobblesurvival/guardians/<zone>.json:
  the strongest walking (or swimming) Pokemon of the zone at band top + 5,
  with the drops from world/zones.json. Boss drops follow Adrian's rule:
  Icy Rocks before Sunscorch, Heat Rocks before Frostpeak.
- Goat Fur and Hoglin Hide recipes make 8 per rock, so one guardian's 3
  rocks pay for one full insulating set.
- Self-test guardian_appears_and_returns; hazard tests cleaned up; the
  zone generator reads Cobblemon's own entries from the field guide's
  hidden_spawns.

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

docs/design.md

@@ -109,6 +109,12 @@ Order of play the bands suggest: Button Isle → Southwold → Westmarch or Jung
 - Basalt Furnace got Durant, Torkoal and Heatmor pinned to it: its own lines were all big (Charizard, Turtonator, Centiskorch, …) and Cobblemon only spawns a Pokémon where its body fits, so cramped basalt caves stayed empty.
 - Tested: `spawn_pools_are_zoned` (no Cobblemon default spawn is left; every entry has a zone and spawns within its band) and `spawn_survey` (a player at a point deep inside each zone is offered only that zone's spawns, and at least one), both in `tools/quick_check.py`.
 
+**Alpha guardians** (Phase 3, step 4; Adrian, 2026-10-29: fixed spots, back 5 hours after being beaten):
+- One per zone except the Shallows, Lush Caves and Dripstone; the Basalt Furnace gets its boss in Phase 7. Each stands at its zone's sample point (deep inside the zone; a cave floor for the Deep Dark) and only appears while a player is within 96 blocks; it wanders no further than 24 blocks.
+- The guardian is the strongest Pokémon that spawns walking (or, at sea, swimming) in its zone, five levels above the band, half again as big, and uncatchable: Pachirisu (Button Isle), Sigilyph (Southwold), Carbink (Westmarch), Tangrowth (Jungle), Arcanine (Mire), Cinderace (Highlands), Delphox (Sunscorch), Tyranitar (Frostpeak), Kingdra (Deep Sea), Dusknoir (Deep Dark). `world/zones.json` → `guardian.species` overrides the pick.
+- Beating it in a battle gives every player in that battle its drops (the chain above: Icy Rocks before Sunscorch, Heat Rocks before Frostpeak, ...). It returns after 5 hours of game time, which only passes while the server runs. Cobblemon's Habitat Blocks were the roadmap's idea, but they can't wait a set time after a defeat or carry custom drops, so the companion mod runs guardians (`zone/Guardians.kt`; state in the world save; `/cobblesurvival guardians` for operators). Definitions: `datapacks/core/data/cobblesurvival/guardians/<zone>.json`, written by `tools/zone_spawns.py`.
+- Tested: `guardian_appears_and_returns` (appears big and uncatchable at its level, beaten in a real battle, drops arrive, stays away, returns after its time).
+
 **Hazards** (Phase 3, step 5), with Cold Sweat 2.4.4:
 - Cold and heat follow the biome: Frostpeak's jagged peaks freeze an unprotected player in about a minute even at noon, Sunscorch's desert and badlands overheat one in about two minutes at noon; deserts cool off at night. Cold Sweat's insulation doesn't move the comfortable range, it slows how fast the body drifts out of it.
 - Only Cold Sweat's fur set (cold) and hide set (heat) really insulate: about 14 minutes in Frostpeak at noon and 25 in Sunscorch, longer with extra fur or hide sewn in. Their materials need boss drops (Adrian's rule): Goat Fur from wool and a Heat Rock (Sunscorch's guardian), Hoglin Hide from leather and an Icy Rock (the Mire's and the Highlands' guardians), `kubejs/server_scripts/insulation.js`. Leather armour no longer insulates by itself; sewn-in leather and wool only a little. Fire Resistance and Cold Sweat's own potions and warm/cold food still work.