Bump version to 2.1.0

Three places carry the version, not the one the release docs mention:
RpkConstants.Version is the user-facing string, surfacing in `rpk
--version` and the web UI footer; RackPeek.csproj carries AssemblyVersion
and the README carries the badge.

AGENTS.md section 4 only names the csproj, so RpkConstants would have
shipped a v2.0.0 label on a 2.1.0 release.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

README.md

@@ -1,6 +1,6 @@
 [![RackPeek demo](./assets/rackpeek_banner_thin.png)](./assets/rackpeek_banner_thin.png)
 
-![Version](https://img.shields.io/badge/Version-2.0.0-2ea44f) ![Status](https://img.shields.io/badge/Status-Stable-success)
+![Version](https://img.shields.io/badge/Version-2.1.0-2ea44f) ![Status](https://img.shields.io/badge/Status-Stable-success)
 [![Join our Discord](https://img.shields.io/badge/Discord-Join%20Us-7289DA?logo=discord&logoColor=white)](https://discord.gg/egXRPdesee) [![Live Demo](https://img.shields.io/badge/Live%20Demo-Try%20RackPeek%20Online-2ea44f?logo=githubpages&logoColor=white)](https://timmoth.github.io/RackPeek/) [![Docker Hub](https://img.shields.io/badge/Docker%20Hub-rackpeek-2496ED?logo=docker&logoColor=white)](https://hub.docker.com/r/aptacode/rackpeek/)
 
 RackPeek is a webui & CLI tool for documenting and managing home lab and small-scale IT infrastructure.

RackPeek.Domain/RpkConstants.cs

@@ -1,7 +1,7 @@
 namespace RackPeek.Domain;
 
 public static class RpkConstants {
-    public const string Version = "v2.0.0";
+    public const string Version = "v2.1.0";
 
     public static bool HasGitServices { get; set; }
 }

RackPeek/RackPeek.csproj

@@ -5,7 +5,7 @@
         <TargetFramework>net10.0</TargetFramework>
         <ImplicitUsings>enable</ImplicitUsings>
         <Nullable>enable</Nullable>
-        <AssemblyVersion>2.0.0</AssemblyVersion>
+        <AssemblyVersion>2.1.0</AssemblyVersion>
     </PropertyGroup>
 
     <ItemGroup>