Fix Cobblemon Pokemon Experience

The mod listens for Cobblemon's battle fainted event and grants experience to the Pokemon that took part as soon as an opposing Pokemon is knocked out. It also blocks the default distribution that normally runs when a battle ends, which prevents the same experience from being counted twice. The behavior follows the way the mainline Pokemon games handle experience, and the mod is aimed at trainer battles where a player faces several Pokemon in a row.

Trainer battles with several Pokemon previously paid experience only after the trainer's last Pokemon was defeated. Trainer mods such as Radical Cobblemon Trainers can make this a problem, and the mod addresses it by paying out on each knockout. Experience works with Exp Share items in the same way as vanilla Cobblemon. Level-ups happen mid-battle and are announced in battle chat, while the summary screen and party overlay display the new level.

Because Cobblemon's Showdown-based battle simulator calculates stats once at the start of a battle, a level-up does not change combat stats until the Pokemon leaves and re-enters the field. The mod is server-side only, so players join without installing it, and a configuration file is needed. It requires Cobblemon, Fabric API, Fabric Language Kotlin and Kotlin for Forge, and is released under the GNU Lesser General Public License v3.0 only, which makes it open source. Builds cover 1.21.1 for Fabric and NeoForge.