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>

mod/build.gradle.kts

@@ -12,6 +12,7 @@ val minecraftVersion = property("minecraft_version") as String
 val neoforgeVersion = property("neoforge_version") as String
 val cobblemonVersion = property("cobblemon_version") as String
 val kotlinforforgeVersion = property("kotlinforforge_version") as String
+val jeiVersion = property("jei_version") as String
 
 group = "dev.cobblesurvival"
 version = modVersion
@@ -32,6 +33,8 @@ repositories {
     maven("https://thedarkcolour.github.io/KotlinForForge/")
     // Cobblemon's coordinates come from its official MDK, not guessed.
     maven("https://artefacts.cobblemon.com/releases/")
+    // JEI's own Maven, as its README gives it (Phase 8: the pack's drop sources as JEI pages).
+    maven("https://maven.blamejared.com/")
 }
 
 dependencies {
@@ -41,6 +44,7 @@ dependencies {
 
     modCompileOnly("com.cobblemon:mod:$cobblemonVersion") { isTransitive = false }
     modImplementation("com.cobblemon:neoforge:$cobblemonVersion")
+    modCompileOnly("mezz.jei:jei-$minecraftVersion-neoforge-api:$jeiVersion")
     implementation("thedarkcolour:kotlinforforge-neoforge:$kotlinforforgeVersion") {
         exclude("net.neoforged.fancymodloader", "loader")
     }