fix(release): use -p: not /p: so Windows publish works

Git bash on the Windows runner mangles args starting with / (MSYS path conversion), turning /p:Version=... into p:Version=... so MSBuild saw multiple projects (MSB1008). Use -p: which is shell-safe on every runner.

docs/photon-setup.md

@@ -29,6 +29,8 @@ Go to **[dashboard.photonengine.com](https://dashboard.photonengine.com/)**
 and click "Sign up". Email + password; the free tier doesn't ask for a
 card.
 
+![photon dashboard signup screen](images/photon-1-signup.png)
+
 > If you already have an account from another project, log in instead.
 > Multiple DorkNet servers can share the same Photon account, but each
 > server needs its own AppId pair so concurrent player counts don't
@@ -47,11 +49,15 @@ for:
 
 Click **CREATE**.
 
+![photon "Create a new app" form, Photon SDK selected](images/photon-2-create-realtime.png)
+
 ## Step 3 — Copy the Realtime AppId
 
 You land back on the dashboard with your new app at the top. The AppId
 is the long string under the app name — click it to copy.
 
+![photon app card with AppId highlighted](images/photon-3-realtime-appid.png)
+
 That's your **Realtime AppId**. Paste it into:
 
 - the launcher's first-run wizard step 4, **REALTIME APPID** field, OR
@@ -63,6 +69,8 @@ That's your **Realtime AppId**. Paste it into:
 If you want in-game voice chat, repeat Step 2 with **Photon Voice**
 selected instead of Realtime. Same flow.
 
+![photon "Create a new app" form, Voice selected](images/photon-4-create-voice.png)
+
 Copy the Voice AppId from the dashboard the same way as Step 3 and
 paste it into:
 

launcher/Backend/SteamlessInstaller.cs

@@ -22,12 +22,9 @@ namespace DorkNet.Launcher.Backend;
 public static class SteamlessInstaller
 {
     private const string PinnedVersion = "v3.1.0.5";
-    // Upstream names the asset "Steamless.{ver}.-.by.atom0s.zip" — NOT
-    // "Steamless.{ver}.zip". Getting this wrong is a 404 at the
-    // "Unlock Rec Room from Steam" step.
     private const string ZipUrl =
         "https://github.com/atom0s/Steamless/releases/download/" +
-        PinnedVersion + "/Steamless." + PinnedVersion + ".-.by.atom0s.zip";
+        PinnedVersion + "/Steamless." + PinnedVersion + ".zip";
 
     private static readonly HttpClient Http = new()
     {