Show empty aux slot on flex mounts with one aux mounted

Remaining fix for #712

src/module/helpers/item.ts

@@ -619,12 +619,17 @@ export function mechLoadoutWeaponSlot(
   let weapon: LancerMECH_WEAPON | null = resolveHelperDotpath(options, weapon_path);
   if (!weapon) {
     // Make an empty ref. Note that it still has path stuff if we are going to be dropping things here
+    const slotSize = size
+      ? size === FittingSize.Flex
+        ? `${FittingSize.Main} || ${FittingSize.Auxiliary}`
+        : size
+      : "any";
     return `
       <div class="${EntryType.MECH_WEAPON} ref slot drop-settable card flexrow" 
            data-path="${weapon_path}" 
            data-accept-types="${EntryType.MECH_WEAPON}">
         <img class="ref-icon" src="${TypeIcon(EntryType.MECH_WEAPON)}"></img>
-        <span class="major">Insert ${size ? size : "any"} weapon</span>
+        <span class="major">Insert ${slotSize} weapon</span>
       </div>`;
   } else {
     return mechWeaponDisplay(weapon_path, mod_path, options);

src/module/helpers/loadout.ts

@@ -1,5 +1,5 @@
 import type { HelperOptions } from "handlebars";
-import { EntryType, SystemType } from "../enums";
+import { EntryType, FittingSize, MountType, SystemType, WeaponSize } from "../enums";
 import {
   inc_if,
   resolveHelperDotpath,
@@ -146,6 +146,21 @@ function weaponMount(mount_path: string, options: HelperOptions): string {
       options
     )
   );
+  // Add an empty aux slot for flex mounts with 1 aux
+  if (
+    mount.type === "Flex" &&
+    mount.slots.length === 1 &&
+    mount.slots[0].weapon?.value?.system.size === WeaponSize.Aux
+  ) {
+    slots.push(
+      mechLoadoutWeaponSlot(
+        `${mount_path}.slots.1.weapon.value`,
+        `${mount_path}.slots.1.mod.value`,
+        FittingSize.Auxiliary,
+        options
+      )
+    );
+  }
   let err = mech.loadoutHelper.validateMount(mount) ?? "";
 
   // FLEX mount: Don't show the empty aux if a main is equipped.