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>

tools/smoke_allowlist.txt

@@ -10,3 +10,7 @@ Failed to parse jigsaw replacement state 'minecraft:dirt_block'
 # Cobblemon 1.8.4 bug: habitats/parched_peat_bog7.nbt has a jigsaw block whose final state is the misspelt
 # "minecraft:strucutre_void". Logged at worldgen; the piece still generates (as air there).
 Failed to parse jigsaw replacement state 'minecraft:strucutre_void'
+# Cobbreeding 2.4.1 lists PastureGUIMixin (a mixin into Cobblemon's client-only pasture screen) among its
+# common mixins, so on a dedicated server Mixin looks up the screen's superclass once while preparing and
+# NeoForge logs this. The screen never loads on a server; the server and Cobbreeding work (self-tests).
+Attempted to load class net/minecraft/client/gui/screens/Screen for invalid dist DEDICATED_SERVER