docs(npc): document null player contract for dialogues() method

Author: Swofty-Developments

type.generic/src/main/java/net/swofty/type/generic/entity/npc/HypixelNPC.java

@@ -233,6 +233,8 @@ public CompletableFuture<String> setDialogue(HypixelPlayer player, String key) {
      * Return an array of DialogueSet objects keyed by unique identifiers.
      *
      * @param player The player to get dialogues for (they can be different per-player).
+     *               May be null when called from {@link #hasDialogue()} — implementations
+     *               must handle null gracefully (e.g. return a default set).
      * @return Array of DialogueSet definitions.
      */
     protected DialogueSet[] dialogues(HypixelPlayer player) {