Phase 8: the pack's own JEI pages for every drop source

Adrian, 2026-11-02/03: every item that can drop gets a JEI page naming its
sources, alongside the Cobblemon Info add-on (which shows drops and biomes,
not zones). The companion mod's JEI plugin (jei/DropSourcesJei.kt) adds:
- Pokemon drops on the island: 794 species of lines that live on the
  island, with chances, amounts and the zones they spawn in (or where their
  line lives); spawns with their own drops (Beheeyem in the End). The Drop
  Synthesizer core is the catalyst.
- Guardians and the End boss; Sacrifice Altar tiers and specials; Rebirth
  Chamber; zone ore veins with regrow times; Cobblebase pasture finds per
  skill and zone.

JEI runs on the client, so the pages read assets/cobblesurvival/jei/
drop_sources.json inside the mod, written by tools/jei_sources.py from the
pack's files. Self-tests drop_sources_match_the_server (file vs live server:
drops, zones, own-drop spawns, guardians, End boss, altar) and
jei_pages_build (every page builds, every item exists). The ore a vein gives
moved into world/zones.json (ores -> item), shared with the quest book.
JEI's API (19.64.0.455) is a compile-only dependency from JEI's own Maven.
Self-tests and the island check pass.

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

tools/quests.py

@@ -161,7 +161,8 @@ def zone_data():
         pool = DATA / f"spawn_pool_world/{zid}.json"
         spawns = json.loads(pool.read_text())["spawns"] if pool.exists() else []
         z["species"] = sorted({f"cobblemon:{s['pokemon'].split()[0].lower()}" for s in spawns})
-        z["veins"] = sorted({n["vein"] for n in nodes if n["zone"] == zid})
+        # What its ore veins give when mined (world/zones.json → ores → item; veins are named <ore>_node).
+        z["ore_items"] = [plan["ores"][v.removesuffix("_node")]["item"] for v in sorted({n["vein"] for n in nodes if n["zone"] == zid})]
         guardian = DATA / f"guardians/{zid}.json"
         z["guardian_data"] = json.loads(guardian.read_text()) if guardian.exists() else None
     return zones
@@ -194,7 +195,7 @@ def title_case(item):
 
 def zone_fields(zone, chapter, book):
     g = zone["guardian_data"]
-    ores = [book["ore_items"][v] for v in zone["veins"] if v in book["ore_items"]]
+    ores = zone["ore_items"]
     return {
         "zone": zone["name"], "zone_id": zone["id"], "low": zone["levels"][0], "high": zone["levels"][1],
         "hazard_text": chapter.get("hazard_text", ""),