Phase 5: breeding with Cobbreeding, Ditto a rare Deep Dark find

Adrian (2026-10-31): add Cobbreeding without a gate; only Ditto should
be rare, in an endgame area or gated behind something else.

- Cobbreeding 2.4.1 (Modrinth only) and Cloth Config (client) in the
  pack; Cobblebase's hatchery takes Cobbreeding's eggs.
- Ditto moved from Button Isle to the Deep Dark with both of Cobblemon's
  entries (rare in slime chunks, ultra-rare elsewhere): zone_spawns.py
  pins take {"zone", "all_entries"}; Deep Dark target +1, Button Isle -1
  so no other line moved; Southwold and Frostpeak guardians pinned (they
  tie on base stats and flipped between runs).
- HMs' Trainer Ditto is made uncatchable; it still trades.
- check_deps.py skips other-side dependencies; Cobbreeding's harmless
  client-mixin log line allowlisted.
- Self-tests cobbreeding_eggs_fit_the_hatchery, trainer_ditto_cant_be_caught;
  docs, balance table, Phase 5 checklist.

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

world/zones.json

@@ -29,14 +29,15 @@
     "dawn_stone": {"zone": "frostpeak", "stone": "cobblemon:dawn_stone_ore", "deepslate": "cobblemon:deepslate_dawn_stone_ore", "regen_minutes": 75, "nodes": {"chance": 0.04, "radius": [0, 0]}, "veins": {"radius": [1, 2], "y": [-16, 320], "spacing": 10, "attempts": 2}},
     "dusk_stone": {"zone": "deep_dark", "deepslate": "cobblemon:deepslate_dusk_stone_ore", "regen_minutes": 75, "nodes": {"chance": 0.1, "tries": 8, "radius": [0, 1], "y": [-64, -24]}}
   },
-  "species": {"durant": "basalt", "torkoal": "basalt", "heatmor": "basalt"},
+  "species": {"durant": "basalt", "torkoal": "basalt", "heatmor": "basalt",
+    "ditto": {"zone": "deep_dark", "all_entries": true}},
   "zones": [
     {
-      "id": "button_isle", "guardian": {"drops": [["cobblemon:poke_ball", 10], ["cobblemon:potion", 4]]}, "lines": 20, "name": "Button Isle", "levels": [2, 10], "hazard": "none", "color": "#a6d96a",
+      "id": "button_isle", "guardian": {"drops": [["cobblemon:poke_ball", 10], ["cobblemon:potion", 4]]}, "lines": 19, "name": "Button Isle", "levels": [2, 10], "hazard": "none", "color": "#a6d96a",
       "rule": {"within": 300}
     },
     {
-      "id": "frostpeak", "guardian": {"drops": [["cobblemon:icy_rock", 3], ["cobblemon:exp_candy_l", 2]]}, "lines": 30, "name": "Frostpeak Range", "levels": [40, 55], "hazard": "cold (Cold Sweat): needs wool insulation", "color": "#f2f7ff",
+      "id": "frostpeak", "guardian": {"species": "tyranitar", "drops": [["cobblemon:icy_rock", 3], ["cobblemon:exp_candy_l", 2]]}, "lines": 30, "name": "Frostpeak Range", "levels": [40, 55], "hazard": "cold (Cold Sweat): needs wool insulation", "color": "#f2f7ff",
       "rule": {"biomes": ["minecraft:jagged_peaks"], "absorb": {"minecraft:windswept_hills": 96, "minecraft:cherry_grove": 144}}
     },
     {
@@ -60,7 +61,7 @@
       "rule": {"region": {"z_max": 0, "x_max": -250}}
     },
     {
-      "id": "southwold", "guardian": {"drops": [["cobblemon:great_ball", 6], ["cobblemon:exp_candy_s", 4]]}, "lines": 35, "name": "Southwold", "levels": [8, 18], "hazard": "none", "color": "#7cc576",
+      "id": "southwold", "guardian": {"species": "pinsir", "drops": [["cobblemon:great_ball", 6], ["cobblemon:exp_candy_s", 4]]}, "lines": 35, "name": "Southwold", "levels": [8, 18], "hazard": "none", "color": "#7cc576",
       "rule": {"region": {"z_min": 0}}
     },
     {
@@ -75,7 +76,7 @@
   "caves": [
     {"id": "lush_caves", "types": ["grass", "bug", "fairy", "poison", "water"], "lines": 20, "name": "Lush Caves", "biome": "minecraft:lush_caves", "levels": [12, 28], "hazard": "none"},
     {"id": "dripstone", "types": ["rock", "ground", "steel", "fairy", "psychic", "dragon"], "lines": 20, "name": "Dripstone Depths", "biome": "minecraft:dripstone_caves", "levels": [22, 38], "hazard": "none"},
-    {"id": "deep_dark", "types": ["ghost", "dark", "steel", "poison", "psychic", "rock"], "guardian": {"drops": [["cobblemon:icy_rock", 3], ["cobblemon:exp_candy_l", 2]]}, "lines": 20, "name": "Deep Dark", "biome": "minecraft:deep_dark", "levels": [45, 60], "hazard": "darkness (vanilla sculk; no Warden)"},
+    {"id": "deep_dark", "types": ["ghost", "dark", "steel", "poison", "psychic", "rock"], "guardian": {"drops": [["cobblemon:icy_rock", 3], ["cobblemon:exp_candy_l", 2]]}, "lines": 21, "name": "Deep Dark", "biome": "minecraft:deep_dark", "levels": [45, 60], "hazard": "darkness (vanilla sculk; no Warden)"},
     {"id": "basalt", "types": ["fire", "rock", "ground", "steel", "dark"], "lines": 15, "name": "Basalt Furnace", "biome": "minecraft:basalt_deltas", "levels": [55, 70], "hazard": "heat (Cold Sweat)"}
   ]
 }