Restructured the project structure back to the way it was, there's no reasonable way to split the modules

src/NadekoBot/_common/Attributes/AliasesAttribute.cs

@@ -0,0 +1,12 @@
+using System.Runtime.CompilerServices;
+
+namespace NadekoBot.Common.Attributes;
+
+[AttributeUsage(AttributeTargets.Method)]
+public sealed class AliasesAttribute : AliasAttribute
+{
+    public AliasesAttribute([CallerMemberName] string memberName = "")
+        : base(CommandNameLoadHelper.GetAliasesFor(memberName))
+    {
+    }
+}

src/NadekoBot/_common/Attributes/CmdAttribute.cs

@@ -0,0 +1,18 @@
+using System.Runtime.CompilerServices;
+
+namespace NadekoBot.Common.Attributes;
+
+[AttributeUsage(AttributeTargets.Method)]
+public sealed class CmdAttribute : CommandAttribute
+{
+    public string MethodName { get; }
+
+    public CmdAttribute([CallerMemberName] string memberName = "")
+        : base(CommandNameLoadHelper.GetCommandNameFor(memberName))
+    {
+        MethodName = memberName.ToLowerInvariant();
+        Aliases = CommandNameLoadHelper.GetAliasesFor(memberName);
+        Remarks = memberName.ToLowerInvariant();
+        Summary = memberName.ToLowerInvariant();
+    }
+}

src/NadekoBot/_common/Attributes/DIIgnoreAttribute.cs

@@ -0,0 +1,11 @@
+#nullable disable
+namespace NadekoBot.Common;
+
+/// <summary>
+/// Classed marked with this attribute will not be added to the service provider 
+/// </summary>
+[AttributeUsage(AttributeTargets.Class)]
+public class DIIgnoreAttribute : Attribute
+{
+    
+}

src/NadekoBot/_common/Attributes/NadekoOptionsAttribute.cs

@@ -0,0 +1,7 @@
+namespace NadekoBot.Common.Attributes;
+
+[AttributeUsage(AttributeTargets.Method)]
+public sealed class NadekoOptionsAttribute<TOption> : Attribute
+    where TOption: INadekoCommandOptions
+{
+}

src/NadekoBot/_common/Attributes/NoPublicBotAttribute.cs

@@ -0,0 +1,21 @@
+#nullable disable
+using System.Diagnostics.CodeAnalysis;
+
+namespace NadekoBot.Common;
+
+[AttributeUsage(AttributeTargets.Method | AttributeTargets.Class)]
+[SuppressMessage("Style", "IDE0022:Use expression body for methods")]
+public sealed class NoPublicBotAttribute : PreconditionAttribute
+{
+    public override Task<PreconditionResult> CheckPermissionsAsync(
+        ICommandContext context,
+        CommandInfo command,
+        IServiceProvider services)
+    {
+#if GLOBAL_NADEKO
+        return Task.FromResult(PreconditionResult.FromError("Not available on the public bot. To learn how to selfhost a private bot, click [here](https://nadekobot.readthedocs.io/en/latest/)."));
+#else
+        return Task.FromResult(PreconditionResult.FromSuccess());
+#endif
+    }
+}

src/NadekoBot/_common/Attributes/OnlyPublicBotAttribute.cs

@@ -0,0 +1,21 @@
+#nullable disable
+using System.Diagnostics.CodeAnalysis;
+
+namespace NadekoBot.Common;
+
+[AttributeUsage(AttributeTargets.Method | AttributeTargets.Class)]
+[SuppressMessage("Style", "IDE0022:Use expression body for methods")]
+public sealed class OnlyPublicBotAttribute : PreconditionAttribute
+{
+    public override Task<PreconditionResult> CheckPermissionsAsync(
+        ICommandContext context,
+        CommandInfo command,
+        IServiceProvider services)
+    {
+#if GLOBAL_NADEKO || DEBUG
+        return Task.FromResult(PreconditionResult.FromSuccess());
+#else
+        return Task.FromResult(PreconditionResult.FromError("Only available on the public bot."));
+#endif
+    }
+}

src/NadekoBot/_common/Attributes/OwnerOnlyAttribute.cs

@@ -0,0 +1,19 @@
+using Microsoft.Extensions.DependencyInjection;
+
+namespace NadekoBot.Common.Attributes;
+
+[AttributeUsage(AttributeTargets.Method | AttributeTargets.Class)]
+public sealed class OwnerOnlyAttribute : PreconditionAttribute
+{
+    public override Task<PreconditionResult> CheckPermissionsAsync(
+        ICommandContext context,
+        CommandInfo command,
+        IServiceProvider services)
+    {
+        var creds = services.GetRequiredService<IBotCredsProvider>().GetCreds();
+
+        return Task.FromResult(creds.IsOwner(context.User) || context.Client.CurrentUser.Id == context.User.Id
+            ? PreconditionResult.FromSuccess()
+            : PreconditionResult.FromError("Not owner"));
+    }
+}

src/NadekoBot/_common/Attributes/RatelimitAttribute.cs

@@ -0,0 +1,38 @@
+using Microsoft.Extensions.DependencyInjection;
+
+namespace NadekoBot.Common.Attributes;
+
+[AttributeUsage(AttributeTargets.Method)]
+public sealed class RatelimitAttribute : PreconditionAttribute
+{
+    public int Seconds { get; }
+
+    public RatelimitAttribute(int seconds)
+    {
+        if (seconds <= 0)
+            throw new ArgumentOutOfRangeException(nameof(seconds));
+
+        Seconds = seconds;
+    }
+
+    public override async Task<PreconditionResult> CheckPermissionsAsync(
+        ICommandContext context,
+        CommandInfo command,
+        IServiceProvider services)
+    {
+        if (Seconds == 0)
+            return PreconditionResult.FromSuccess();
+
+        var cache = services.GetRequiredService<IBotCache>();
+        var rem = await cache.GetRatelimitAsync(
+            new($"precondition:{context.User.Id}:{command.Name}"),
+            Seconds.Seconds());
+
+        if (rem is null)
+            return PreconditionResult.FromSuccess();
+
+        var msgContent = $"You can use this command again in {rem.Value.TotalSeconds:F1}s.";
+
+        return PreconditionResult.FromError(msgContent);
+    }
+}

src/NadekoBot/_common/Attributes/UserPermAttribute.cs

@@ -0,0 +1,29 @@
+using Microsoft.Extensions.DependencyInjection;
+
+namespace Discord;
+
+[AttributeUsage(AttributeTargets.Method, AllowMultiple = true)]
+public class UserPermAttribute : RequireUserPermissionAttribute
+{
+    public UserPermAttribute(GuildPerm permission)
+        : base(permission)
+    {
+    }
+
+    public UserPermAttribute(ChannelPerm permission)
+        : base(permission)
+    {
+    }
+
+    public override Task<PreconditionResult> CheckPermissionsAsync(
+        ICommandContext context,
+        CommandInfo command,
+        IServiceProvider services)
+    {
+        var permService = services.GetRequiredService<IDiscordPermOverrideService>();
+        if (permService.TryGetOverrides(context.Guild?.Id ?? 0, command.Name.ToUpperInvariant(), out _))
+            return Task.FromResult(PreconditionResult.FromSuccess());
+
+        return base.CheckPermissionsAsync(context, command, services);
+    }
+}