put the settings in the panel header

They were floating buttons over the top-right of the iframe, which was wrong
twice: they sit on top of Gitea's own controls, and an overlay on an
application that fills its whole panel is invisible until you already know it
is there. Reported as "I have no access to settings when the iframe is loaded",
which is exactly right.

The header is the platform's own furniture — always present, never competing
with the content underneath — and it is where photos and jellyfin put theirs.
It also names where you are, so /gitea/connection reads as "Gitea —
connection" rather than looking like the frame failed to load.

web/GiteaFrame.tsx

@@ -1,8 +1,7 @@
 import { useEffect, useState } from 'react';
-import { Link, useParams } from 'react-router';
-import { ExternalLink, Loader2, Plug, TriangleAlert } from 'lucide-react';
+import { useParams } from 'react-router';
+import { Loader2, TriangleAlert } from 'lucide-react';
 import { useClient } from 'hooks/useClient';
-import { Button } from '@/components/ui/button';
 import { GiteaConnection, type ConnectionState } from './GiteaConnection';
 
 // Gitea's own web interface, rendered in place.
@@ -99,22 +98,6 @@ export const GiteaFrame = () => {
       {/* The escape hatch, and it is not an admission of defeat: the whole point of proxying an app that
           already has a UI is that its own UI stays available. Anything the frame handles badly, this
           opens properly. */}
-      <div className="absolute right-3 top-3 z-10 flex gap-1.5 opacity-60 transition-opacity hover:opacity-100">
-        {/* A real link, not a button: it is navigation, and it should be cmd-clickable like any other. */}
-        <Button size="sm" variant="outline" asChild title="Connection settings">
-          <Link to="/gitea/connection">
-            <Plug className="h-3.5 w-3.5" />
-          </Link>
-        </Button>
-        <Button
-          size="sm"
-          variant="outline"
-          onClick={() => window.open(FRAME_SRC, '_blank', 'noopener')}
-          title="Open Gitea in a new tab"
-        >
-          <ExternalLink className="h-3.5 w-3.5" />
-        </Button>
-      </div>
       <iframe
         src={FRAME_SRC}
         title="Gitea"