Fix ResPath CanonPath

Robust.Server/ServerOptions.cs

@@ -29,12 +29,12 @@ public sealed class ServerOptions
         /// <summary>
         ///     Directory to load all assemblies from.
         /// </summary>
-        public ResPath AssemblyDirectory { get; init; } = new(@"/Assemblies");
+        public ResPath AssemblyDirectory { get; init; } = new(@"/Assemblies/");
 
         /// <summary>
         ///     Directory to load all prototypes from.
         /// </summary>
-        public ResPath PrototypeDirectory { get; init; } = new(@"/Prototypes");
+        public ResPath PrototypeDirectory { get; init; } = new(@"/Prototypes/");
 
         /// <summary>
         ///     Whether to disable mounting the "Resources/" folder on FULL_RELEASE.

Robust.Shared/ContentPack/ModLoader.cs

@@ -77,7 +77,7 @@ public bool TryLoadModulesFrom(ResPath mountPath, string filterPrefix)
             var paths = new List<ResPath>();
 
             foreach (var filePath in _res.ContentFindRelativeFiles(mountPath)
-                         .Where(p => !p.ToString().Contains('/') && p.Filename.StartsWith(filterPrefix) &&
+                         .Where(p => p.Filename.StartsWith(filterPrefix) &&
                                      p.Extension == "dll"))
             {
                 var fullPath = mountPath / filePath;

Robust.Shared/ContentPack/ResourceManager.cs

@@ -379,7 +379,10 @@ public IEnumerable<ResPath> GetContentRoots()
             {
                 if (root is DirLoader loader)
                 {
-                    yield return new ResPath(loader.GetPath(new ResPath(@"/")));
+                    // Sanitise platform specific path.
+                    var rootDir = loader.GetPath(new ResPath(@"/")).Replace(Path.DirectorySeparatorChar, '/');
+
+                    yield return new ResPath(rootDir);
                 }
             }
         }

Robust.Shared/Utility/ResPath.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Diagnostics.CodeAnalysis;
+using System.IO;
 using System.Text;
 using System.Text.Json.Serialization;
 using JetBrains.Annotations;
@@ -64,6 +65,8 @@ namespace Robust.Shared.Utility;
 
     public ResPath(string canonPath)
     {
+        // Paths should never have non-standardised directory separators passed in, the caller should have already sanitised it.
+        DebugTools.Assert(!canonPath.Contains('\\'));
         CanonPath = canonPath;
     }