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>

docs/roadmap.md

@@ -132,6 +132,8 @@ Goal: ore, Pokémon drops and base production form the economy.
 
 Goal: moves a Pokémon knows act on the world, HM-style. Flamethrower sets blocks on fire.
 
+**Decided 2026-10-31 (Adrian):** the field moves come from Cobblemon HMs instead of the spec below; mining ore is the one hard requirement, and furnaces are lit by a Pokémon inside a Phase 6 machine. See `docs/design.md`.
+
 **Prior art to study, not depend on.** None is confirmed on Cobblemon 1.8:
 
 - [Cobblemon Field Survival](https://www.modpackindex.com/mod/173947/cobblemon-field-survival) (NeoForge 1.21.1, Cobblemon 1.7.3): mining, digging, water utilities, Fire types cooking food.