Roundstart variation game rules (#24397)

* Raise `StationPostInitEvent` broadcast

* Basic variation pass handling

* standardize names + rule entities

* why does it work like that?

* add to defaults

* light break variation pass

* ent spawn entry

* move some stationevent utility functions to gamerule + add one for finding random tile on specified station

* forgot how statistics works

* powered light variation pass is good now

* station tile count function

* public method to ensure all solutions (for procedural use before mapinit)

* move gamerulesystem utility funcs to partial

* ensure all solutions before spilling in puddlesystem. for use when spilling before mapinit

* trash & puddle variation passes!

* oh yeah

* ehh lets live a little

* std

* utility for game rule check based on comp

* entprotoid the trash spawner oops

* generalize trash variation

* use added instead of started for secret rule

* random cleanup

* generic replacement variation system

* Wall rusting variation rule

* account for modifying while enumerating

* use localaabb

* fix test

* minor tweaks

* reinforced wall replacer + puddletweaker

(cherry picked from commit cc24ba6a317c4bee84ffa1eda8397c255ca92be9)

Content.Server/GameTicking/Rules/VariationPass/PuddleMessVariationPassSystem.cs

@@ -0,0 +1,35 @@
+using Content.Server.Fluids.EntitySystems;
+using Content.Server.GameTicking.Rules.VariationPass.Components;
+using Content.Shared.Chemistry.Components;
+using Content.Shared.Random.Helpers;
+using Robust.Shared.Prototypes;
+using Robust.Shared.Random;
+
+namespace Content.Server.GameTicking.Rules.VariationPass;
+
+/// <inheritdoc cref="PuddleMessVariationPassComponent"/>
+public sealed class PuddleMessVariationPassSystem : VariationPassSystem<PuddleMessVariationPassComponent>
+{
+    [Dependency] private readonly PuddleSystem _puddle = default!;
+    [Dependency] private readonly IPrototypeManager _proto = default!;
+
+    protected override void ApplyVariation(Entity<PuddleMessVariationPassComponent> ent, ref StationVariationPassEvent args)
+    {
+        var totalTiles = Stations.GetTileCount(args.Station);
+
+        if (!_proto.TryIndex(ent.Comp.RandomPuddleSolutionFill, out var proto))
+            return;
+
+        var puddleMod = Random.NextGaussian(ent.Comp.TilesPerSpillAverage, ent.Comp.TilesPerSpillStdDev);
+        var puddleTiles = Math.Max((int) (totalTiles * (1 / puddleMod)), 0);
+
+        for (var i = 0; i < puddleTiles; i++)
+        {
+            if (!TryFindRandomTileOnStation(args.Station, out _, out _, out var coords))
+                continue;
+
+            var sol = proto.Pick(Random);
+            _puddle.TrySpillAt(coords, new Solution(sol.reagent, sol.quantity), out _, sound: false);
+        }
+    }
+}