Dream (Don't) Drop Loadout (#5494)

## Short description
#4958 + Dynamic made it so you can roll antags later into the round, but
this can actually lead to a problem where you end up dropping gear on
the floor. This tries to fix that by dropping things from your equipped
back storage onto the ground if there's not enough room, and, if you're
not weaing back storage, putting it in your hands instead. When both
those cases fail, only then will it drop stuff on the floor.

Pun Pun and others without back storage would actually never get their
gear, so this also allows them to get it via the hand equip.

As I always state when I use AI, I had AI assistance in creating this
PR, mainly with deciphering and rewriting SharedStationSpawningSystem.

## Why we need to add this
Antags dropping their stuff is a pretty bad new player trap.

## Media (Video/Screenshots)

[Content.Client_Kkm9myix1d.webm](https://github.com/user-attachments/assets/3ca35e6a-6b75-4a2b-acfa-7a036d114302)


[Content.Client_6O0N1zPo4J.webm](https://github.com/user-attachments/assets/33e488f3-1a10-45f0-877a-3397f365b4bd)

<img width="363" height="414" alt="image"
src="https://github.com/user-attachments/assets/eeef771c-dea3-41e2-b8a1-0f152ab38845"
/>


## Checks
- [X] I do not require assistance to complete the PR.
- [X] Before posting/requesting review of a PR, I have verified that the
changes work.
- [X] I have added screenshots/videos of the changes, or this PR does
not change in-game mechanics.
- [X] I affirm that my changes are licensed under the [MIT
License](https://github.com/ss14Starlight/space-station-14/blob/Starlight/LICENSE.TXT)
and grant permission for use in this repository under its conditions.

**Changelog**
:cl: wonderfulnewworld
- fix: When you roll an antag that adds items to your inventory, if your
back storage doesn't have enough room, it'll drop enough items from your
back storage to fit your new gear in. If you're not wearing back
storage, or your back storage is too small, it'll put them in your hands
instead. Failing both of those cases, then it'll drop them on the floor.
- fix: Pun Pun and other non-bag equippers can now actually get their
Thief and SELF gear.

Author: wonderfulnewworld

Content.Server/Antag/AntagSelectionSystem.cs

@@ -1158,7 +1158,7 @@ private void InitializeAntag(Entity<AntagSelectionComponent> gameRule, AntagSpec
             gear.Add(prototype.StartingGear.Value);
 
         var selectedLoadout = GetSelectedLoadout(player, selectedProfile, prototype.RoleLoadout, out var selectedLoadoutProto); // Starlight, antag loadouts
-        _loadout.Equip(antag, gear, prototype.RoleLoadout, selectedLoadout, selectedLoadoutProto); // Starlight
+        _loadout.Equip(antag, gear, prototype.RoleLoadout, selectedLoadout, selectedLoadoutProto, prioritizeBackStorage: true); // Starlight
 
         // Ensure that we have the right mind for our entity.
         if (!_mind.TryGetMind(player, out var mind, out var mindComp) || mindComp.OwnedEntity != antag)

Content.Shared/Clothing/LoadoutSystem.cs

@@ -153,17 +153,20 @@ public void Equip(EntityUid uid, List<ProtoId<StartingGearPrototype>>? startingG
         // Starlight edit Start: Antag Loadouts
         List<ProtoId<RoleLoadoutPrototype>>? loadoutGroups,
         RoleLoadout? selectedLoadout = null,
-        RoleLoadoutPrototype? selectedLoadoutProto = null)
+        RoleLoadoutPrototype? selectedLoadoutProto = null, // Starlight
+        bool prioritizeBackStorage = false) // Starlight
         // Starlight edit End
     {
+        var priorityContext = prioritizeBackStorage ? new PriorityStorageEquipContext() : null; // Starlight
+
         // First, randomly pick a startingGear profile from those specified, and equip it.
         if (startingGear != null && startingGear.Count > 0)
-            _station.EquipStartingGear(uid, _random.Pick(startingGear), false);
+            _station.EquipStartingGear(uid, _random.Pick(startingGear), false, priorityContext); // Starlight
 
         // Starlight Start: Antag Loadouts
         if (selectedLoadout != null && selectedLoadoutProto != null)
         {
-            _station.EquipRoleLoadout(uid, selectedLoadout, selectedLoadoutProto);
+            _station.EquipRoleLoadout(uid, selectedLoadout, selectedLoadoutProto, null, priorityContext);
             GearEquipped(uid);
             return;
         }
@@ -181,7 +184,7 @@ public void Equip(EntityUid uid, List<ProtoId<StartingGearPrototype>>? startingG
         var proto = _protoMan.Index(id);
         var loadout = new RoleLoadout(id);
         loadout.SetDefault(GetProfile(uid), _actors.GetSession(uid), _protoMan, true);
-        _station.EquipRoleLoadout(uid, loadout, proto);
+        _station.EquipRoleLoadout(uid, loadout, proto, null, priorityContext); // Starlight
 
         GearEquipped(uid);
     }