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>

pack/mods/cloth-config.pw.toml

@@ -0,0 +1,13 @@
+name = "Cloth Config API"
+filename = "cloth-config-15.0.140-neoforge.jar"
+side = "client"
+
+[download]
+url = "https://cdn.modrinth.com/data/9s6osm5g/versions/izKINKFg/cloth-config-15.0.140-neoforge.jar"
+hash-format = "sha512"
+hash = "aaf9b010955b8cd294e5a92f069985b18729fd5e2cf22d351f1dff9680f15488688803ec41e77e941cbde130ceb535014ca4c868047d80ab69c2d508e216654d"
+
+[update]
+[update.modrinth]
+mod-id = "9s6osm5g"
+version = "izKINKFg"