Phase 9: crafted summons for the legendaries

Adrian, 2026-11-09: legendaries, mythicals, Ultra Beasts and Paradox Pokemon
come from crafted summons. 22 Sigils (Naganadel evolves from Poipole), one
item told apart by custom data, from world/summons.json through
tools/summons.py: late-game recipes in three tiers (Lv 70, 80, 90), each used
in a fitting zone. A summoned legend fights as a boss (area attacks by level
and type, arena 32, the Guardian's Ward) but can be caught; on capture it
loses every boss mark. One at a time within 96 blocks.

Quest book: a Legends chapter, one quest per Sigil (97 quests). JEI lists each
Sigil as its own item, and Island Drops says where a legend is summoned; drops
Cobblemon names but doesn't have (Ho-Oh's Sacred Ash) get no slot.

Self-tests every_implemented_pokemon_is_obtainable (spawn, fossil or Sigil for
every implemented species) and sigil_summons_a_catchable_legend. Self-tests
and the island check pass.

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

docs/design.md

@@ -329,7 +329,11 @@ Adrian's choices: Pokémon with no biome on the island become rare spawns in fit
 **Every implemented Pokémon is obtainable** (roadmap). Of 905 implemented species, 95 were out of reach by wild spawn or by evolving a wild line (2026-11-09):
 - 5 fossils (Aerodactyl, Arctovish, Arctozolt, Dracovish, Dracozolt): already obtainable. The field guide lists their fossils as found on the island, and the fossil machines are craftable.
 - 67 species in 31 lines that spawn only in biomes the island lacks, or not at all (Rotom): each line gets a home in the closest-fitting zone (`world/zones.json` → `homeless`), as a rare spawn anywhere in that zone at its levels. Conditions tied to the missing biomes are dropped. Existing spawns and homes don't move. They show in `docs/zone-species.md` and in JEI.
-- 23 legendaries, mythicals, Ultra Beasts and Paradox Pokémon, with no spawn data: crafted summons (to do).
+- 23 legendaries, mythicals, Ultra Beasts and Paradox Pokémon, with no spawn data: crafted summons (below). Naganadel comes from evolving Poipole, so 22 Sigils.
+
+**Crafted summons** (Adrian, 2026-11-09). Each legend has a Sigil (`cobblesurvival:summon_sigil`, one item told apart by its custom data), crafted from four of a zone material, four of a ring item and a core: tier 1 (Lv 70) diamond and netherite ingot, tier 2 (Lv 80) diamond and nether star, tier 3 (Lv 90: Rayquaza, Mewtwo, Eternatus) netherite ingots and nether star. Used in the zone written on it, it summons a wild one six blocks ahead, one at a time within 96 blocks. It fights like a boss (`bosses/summon_<species>.json`: area attacks by level and type, a 32-block arena, the Guardian's Ward, so at most a quarter of its HP per attack), except it can be caught: the pack's usual catching rules apply. On capture it loses every boss mark and is an ordinary Pokémon. If it's knocked out, the Sigil is spent; if the fight is lost it heals and stays. Which zone, tier and material: `world/summons.json` → `tools/summons.py` (recipes and data, with the name and "use in" text on the recipe's result so the client needs no server data). The quest book has a Legends chapter with a quest per Sigil; JEI lists each Sigil as its own item, and the Island Drops pages say where a legend is summoned. Moltres, Regigigas and Eternatus are guardians too: those stay uncatchable, the summoned ones are separate.
+
+Self-tests: `every_implemented_pokemon_is_obtainable` (every implemented species' line spawns, comes from a fossil or has a Sigil; a new Cobblemon version adding species fails it until they have a home), `sigil_summons_a_catchable_legend`.
 
 **Ore veins** (Adrian, 2026-11-09: more sporadic but bigger). Nodes are about 40 % rarer and veins about 30 % further apart, each one block larger in radius; the bigger size outweighs the spacing, so the island holds 1.5–3× the ore. Veins are laid down when chunks generate, so this needs a newly generated island.