Optimizations from server profile (#38290)

* Properly cache regexes in chat sanitization/accents

Wow I wonder if `new Regex()` has a cost to it *looks at server profile*.

* Avoid lag caused by Tippy command completions

CompletionHelper.PrototypeIDs explicitly says *not* to use it with EntityPrototype. Unsurprisingly, reporting a completion result for every entity prototype in the game is a *bad idea*.

* Add active count metrics to some high-load systems

Mover & NPCs

I suspect the thing that caused the Leviathan round to shit itself on performance is NPC spam in space or something. So let's verify that.

* Enable parallel processing on pow3r again

Originally disabled due to a theory of it causing bugs, it was re-enabled on Vulture, and I'm not aware of it having caused any issues there.

* Replace hashset with bitflags for AtmosMonitor alert types.

Allocating these hashsets was like 20% of the CPU of atmos, somehow.

* Cache HashSet used for space movement collider checks

Turns out this was a ton of server allocations. Huh.

Content.Shared/Movement/Systems/SharedMoverController.cs

@@ -72,6 +72,8 @@ public abstract partial class SharedMoverController : VirtualController
     /// </summary>
     public Dictionary<EntityUid, bool> UsedMobMovement = new();
 
+    private readonly HashSet<EntityUid> _aroundColliderSet = [];
+
     public override void Initialize()
     {
         UpdatesBefore.Add(typeof(TileFrictionController));
@@ -454,7 +456,9 @@ public abstract partial class SharedMoverController : VirtualController
         var (uid, collider, mover, transform) = entity;
         var enlargedAABB = _lookup.GetWorldAABB(entity.Owner, transform).Enlarged(mover.GrabRange);
 
-        foreach (var otherEntity in lookupSystem.GetEntitiesIntersecting(transform.MapID, enlargedAABB))
+        _aroundColliderSet.Clear();
+        lookupSystem.GetEntitiesIntersecting(transform.MapID, enlargedAABB, _aroundColliderSet);
+        foreach (var otherEntity in _aroundColliderSet)
         {
             if (otherEntity == uid)
                 continue; // Don't try to push off of yourself!