Phase 5: field moves from Cobblemon HMs

Adrian (2026-10-31): use Cobblemon HMs; mining ore is the one hard
requirement, furnaces get lit by a Pokemon inside a Phase 6 machine.

- Cobblemon HMs 4.1.0 in the pack (Modrinth), default config.
- Self-test rock_smash_mines_veins: HMs' Rock Smash breaks a
  regenerating vein, the ore drops and the vein becomes a regenerator.
- HMs' Trainer Ditto (a wild Ditto underneath) is exempt from the
  hostility scan and the stray despawn (world/SpecialPokemon.kt).
- Docs: licenses, addon status, design, balance, roadmap note,
  Phase 5 checklist with the open questions for Adrian.

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

pack/mods/cobblemon-hms.pw.toml

@@ -0,0 +1,13 @@
+name = "Cobblemon HMs"
+filename = "cobblemon-hms-neoforge-4.1.0.jar"
+side = "both"
+
+[download]
+url = "https://cdn.modrinth.com/data/JNfSyMuQ/versions/uC02CqRy/cobblemon-hms-neoforge-4.1.0.jar"
+hash-format = "sha512"
+hash = "009f1a6deb011ffa42f29bb784a7de5ddd0233b38da0885e6f8aa70ce5a07c961f853ad5807dd6706f756e191751faf2f096f1df9331c652ca8254302979d437"
+
+[update]
+[update.modrinth]
+mod-id = "JNfSyMuQ"
+version = "uC02CqRy"