fix: re-check soft dependencies after every plugin has enabled

src/main/java/net/tfminecraft/activitytf/ActivityPlugin.java

@@ -46,7 +46,15 @@ public void onEnable() {
         getServer().getPluginManager().registerEvents(new CraftListener(manager), this);
         getServer().getPluginManager().registerEvents(gui, this);
 
-        registerHooks();
+        // Paper can enable soft dependencies after this plugin when their own dependencies form
+        // a cycle, so re-check them once every plugin has finished enabling.
+        getServer().getScheduler().runTask(this, () -> {
+            if (manager.getConfiguration().itemPluginsChanged()) {
+                getLogger().info("An item plugin finished enabling after activity - reloading the config.");
+                manager.reload();
+            }
+            registerHooks();
+        });
 
         getLogger().info("activity has been enabled!");
     }

src/main/java/net/tfminecraft/activitytf/config/ActivityConfiguration.java

@@ -129,12 +129,7 @@ public void load() {
         FileConfiguration config = plugin.getConfig();
         messages.reload();
 
-        List<String> missing = new ArrayList<>();
-        for (String name : List.of("TLibs", "MMOItems", "MythicLib")) {
-            if (!Bukkit.getPluginManager().isPluginEnabled(name)) {
-                missing.add(name);
-            }
-        }
+        List<String> missing = missingItemPathPlugins();
         itemPathsUsable = missing.isEmpty();
         missingItemPathPlugins = String.join(", ", missing);
         itemsAdderUsable = Bukkit.getPluginManager().isPluginEnabled("ItemsAdder");
@@ -1268,6 +1263,25 @@ public boolean itemPathsUsable() {
         return itemPathsUsable;
     }
 
+    private static List<String> missingItemPathPlugins() {
+        List<String> missing = new ArrayList<>();
+        for (String name : List.of("TLibs", "MMOItems", "MythicLib")) {
+            if (!Bukkit.getPluginManager().isPluginEnabled(name)) {
+                missing.add(name);
+            }
+        }
+        return missing;
+    }
+
+    /**
+     * True when an item plugin was enabled or disabled since the last load, e.g. when Paper
+     * breaks a dependency cycle by enabling MMOItems after this plugin.
+     */
+    public boolean itemPluginsChanged() {
+        return itemPathsUsable != missingItemPathPlugins().isEmpty()
+            || itemsAdderUsable != Bukkit.getPluginManager().isPluginEnabled("ItemsAdder");
+    }
+
     public boolean itemsAdderUsable() {
         return itemsAdderUsable;
     }