Add kit system, KitManager and Goblin kit

Introduce a full kit framework and supporting utilities.

- Add core kit API: Kit, Playstyle, ActiveAbility, PassiveAbility, AbilityResult, charge state and PlayerChargeData.
- Implement KitManager for registration, lobby selections, apply/remove/clear lifecycle and charge tracking.
- Add KitEventDispatcher listener to centralize kit event handling (interact, hits, move) and integrate passive/active hooks.
- Provide example kit implementations: GoblinKit (functional abilities) and TemplateKit (reference).
- Add utilities: ItemBuilder and WorldEditUtils (WorldEdit-based sphere creation).
- Integrate into plugin: SpeedHG now initialises KitManager, registers kits and KitEventDispatcher, applies kits at game start and clears on end.
- LanguageManager: add default message/list/component helpers.
- Build changes: bump Kotlin plugin to 2.2.0 and add WorldEdit compileOnly deps; also expose legacySerializer in Extensions.

These changes implement the kit feature set (items, abilities, charge/recharge flow) and wire it into the game lifecycle.

src/main/kotlin/club/mcscrims/speedhg/kit/KitManager.kt

@@ -0,0 +1,144 @@
+package club.mcscrims.speedhg.kit
+
+import club.mcscrims.speedhg.SpeedHG
+import club.mcscrims.speedhg.kit.charge.PlayerChargeData
+import org.bukkit.entity.Player
+import java.util.UUID
+import java.util.concurrent.ConcurrentHashMap
+
+/**
+ * Manages kit registration, player selections, and the charge state for all online players.
+ *
+ * ## Typical usage flow
+ * ```
+ * // During plugin startup
+ * kitManager.registerKit(WarriorKit())
+ * kitManager.registerKit(ArcherKit())
+ *
+ * // During lobby (e.g. GUI click)
+ * kitManager.selectKit(player, kitManager.getKit("warrior")!!)
+ * kitManager.selectPlaystyle(player, Playstyle.AGGRESSIVE)
+ *
+ * // When the game round starts (replace the TODO in GameManager.startGame)
+ * kitManager.applyKit(player)   // gives items, runs onAssign / passive.onActivate
+ *
+ * // When the round ends
+ * kitManager.clearAll()          // runs onRemove / passive.onDeactivate for every player
+ * ```
+ */
+class KitManager(
+	private val plugin: SpeedHG
+) {
+
+	// All kits available this session, keyed by Kit.id
+	private val registeredKits = ConcurrentHashMap<String, Kit>()
+
+	// Lobby selections — set before the round starts
+	private val selectedKits       = ConcurrentHashMap<UUID, Kit>()
+	private val selectedPlaystyles = ConcurrentHashMap<UUID, Playstyle>()
+
+	// Live charge state — populated by applyKit, cleared by removeKit/clearAll
+	private val chargeData = ConcurrentHashMap<UUID, PlayerChargeData>()
+
+	// -------------------------------------------------------------------------
+	//  Kit registration
+	// -------------------------------------------------------------------------
+
+	fun registerKit(
+		kit: Kit
+	) {
+		registeredKits[kit.id] = kit
+		plugin.logger.info("[KitManager] Registered kit: ${kit.id}")
+	}
+
+	fun getRegisteredKits(): Collection<Kit> = registeredKits.values
+
+	fun getKit(id: String): Kit? = registeredKits[id]
+
+	// -------------------------------------------------------------------------
+	//  Player selections (lobby phase)
+	// -------------------------------------------------------------------------
+
+	fun selectKit(
+		player: Player,
+		kit: Kit
+	) {
+		selectedKits[player.uniqueId] = kit
+	}
+
+	/**
+	 * Set the playstyle for a player.
+	 * Defaults to [Playstyle.DEFENSIVE] if never called.
+	 */
+	fun selectPlaystyle(
+		player: Player,
+		playstyle: Playstyle
+	) {
+		selectedPlaystyles[player.uniqueId] = playstyle
+	}
+
+	fun getSelectedKit( player: Player ): Kit? = selectedKits[player.uniqueId]
+
+	fun getSelectedPlaystyle( player: Player ): Playstyle =
+		selectedPlaystyles[player.uniqueId] ?: Playstyle.DEFENSIVE
+
+	// -------------------------------------------------------------------------
+	//  Game lifecycle
+	// -------------------------------------------------------------------------
+
+	/**
+	 * Apply the player's selected kit at game start.
+	 *
+	 * Call this from [GameManager.startGame] for every online player, **after** teleportation.
+	 * If the player has not selected a kit, this is a no-op.
+	 */
+	fun applyKit(
+		player: Player
+	) {
+		val kit       = selectedKits[player.uniqueId] ?: return
+		val playstyle = getSelectedPlaystyle( player )
+		val active    = kit.getActiveAbility( playstyle )
+
+		chargeData[player.uniqueId] = PlayerChargeData( active.hitsRequired )
+
+		kit.onAssign( player, playstyle )
+		kit.getPassiveAbility( playstyle ).onActivate( player )
+		kit.giveItems( player, playstyle )
+	}
+
+	/**
+	 * Remove and clean up a player's kit (round over, player eliminated, etc.).
+	 * Safe to call even if the player has no kit assigned.
+	 */
+	fun removeKit(
+		player: Player
+	) {
+		val kit       = selectedKits[player.uniqueId] ?: return
+		val playstyle = getSelectedPlaystyle( player )
+
+		kit.getPassiveAbility( playstyle ).onDeactivate( player )
+		kit.onRemove( player )
+
+		chargeData.remove( player.uniqueId )
+	}
+
+	/**
+	 * Remove all kits and clear every selection.
+	 * Call this at the end of each round, **before** resetting other game state.
+	 */
+	fun clearAll()
+	{
+		selectedKits.keys.toList().forEach { uuid ->
+			plugin.server.getPlayer( uuid )?.let { removeKit( it ) }
+		}
+		selectedKits.clear()
+		selectedPlaystyles.clear()
+		chargeData.clear()
+	}
+
+	// -------------------------------------------------------------------------
+	//  Charge access (used by KitEventDispatcher)
+	// -------------------------------------------------------------------------
+
+	fun getChargeData( player: Player ): PlayerChargeData? = chargeData[player.uniqueId]
+}