Simplify install command to plain curl, add /dl shortlink

- nginx.conf: add /dl -> latest xetup.exe release redirect (update on each release)
- index.html: replace irm/iex command with 'curl -Lo xetup.exe xetup.x9.cz/dl'
  works with built-in curl.exe on Win10/11, no PowerShell execution policy needed

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

web/index.html

@@ -178,7 +178,7 @@
   </div>
 
   <div class="install-box">
-    <code id="install-cmd">irm xetup.x9.cz/get.ps1 | iex</code>
+    <code id="install-cmd">curl -Lo xetup.exe xetup.x9.cz/dl</code>
     <button id="copy-btn" onclick="copyCmd()">Kopirovat</button>
   </div>
 

web/nginx.conf

@@ -14,6 +14,11 @@ server {
         add_header X-Content-Type-Options nosniff always;
     }
 
+    # Permanent shortlink to latest xetup.exe – update on each release
+    location = /dl {
+        return 302 https://git.xetup.x9.cz/x9/xetup/releases/download/v0.1.0/xetup.exe;
+    }
+
     # Proxy Forgejo API calls so browser doesn't need CORS or direct access to Forgejo
     location /forgejo-api/ {
         proxy_pass         http://xetup-forgejo:3000/api/v1/;