Drop the external demo: the Widgets tab is the demo

The hamlab-demo site, its Widgets-tab button, the demo_url config key and the make publish
target that fed it are all gone, along with the public read-only token it needed. The
example stays in examples/external-demo as something to read. The installer one-liner
already comes from Gitea releases.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

web/src/Gallery.tsx

@@ -31,7 +31,7 @@ function Tile({ spec, data, note }: { spec: WidgetSpec; data: WidgetData; note:
   )
 }
 
-export default function Gallery({ demoUrl }: { demoUrl?: string }) {
+export default function Gallery() {
   const [cat, setCat] = useState<Sensor[] | null>(null)
   const [err, setErr] = useState('')
   const rate = useRefreshMs()
@@ -61,7 +61,6 @@ export default function Gallery({ demoUrl }: { demoUrl?: string }) {
         <span className="hint">{needle ? `${shown.length} of ${sensors.length}` : sensors.length} sensors on this machine · live · tap a tile to copy its ID</span>
         <input className="gallery-find" value={find} onChange={(e) => setFind(e.target.value)} placeholder="find — gitea, temp, enp3s0…" spellCheck={false} autoCapitalize="off" />
         <span className="spacer" />
-        {demoUrl && <a className="btn" href={demoUrl} target="_blank" rel="noreferrer" title="a page outside Ham Lab, built on the same sensor API">External demo ↗</a>}
       </div>
 
       {!needle && <h2 className="section">Widget types</h2>}

web/src/Shell.tsx

@@ -269,7 +269,7 @@ export default function Shell({ me: hubMe, onLoggedOut }: { me: Me; onLoggedOut:
           {view === 'space' && <Space key={machine ?? ''} />}
           {view === 'machines' && <Machines hub={hubMe} onChanged={loadMachines} onOpen={(n) => { switchMachine(n); setView('dashboard') }} />}
           {view === 'dashboard' && <Dashboard />}
-          {view === 'widgets' && <Gallery demoUrl={hubMe.demo_url} />}
+          {view === 'widgets' && <Gallery />}
           {view === 'docker' && <Docker />}
           {view === 'alerts' && <Alerts machines={machines.map((m) => m.name)} titleOf={(n) => titleOf(n === hubMe.host ? null : n, machines, hubMe.host)} />}
           {view === 'top' && <Top />}

web/src/api.ts

@@ -55,7 +55,7 @@ async function req<T>(method: string, path: string, body?: unknown, local = fals
 }
 
 export interface UpdateStatus { current: string; latest: string; arch: string; behind: boolean; checking: boolean; installing: boolean; enabled: boolean; auto: boolean; url: string; notes?: string; published?: string; checked?: string; error?: string }
-export interface Me { demo_url?: string; addr?: string; host: string; user: string; account?: string; update_available?: string; version: string; load: string; uptime: number; reboot_needed?: boolean; fingerprint?: string; arch?: string }
+export interface Me { addr?: string; host: string; user: string; account?: string; update_available?: string; version: string; load: string; uptime: number; reboot_needed?: boolean; fingerprint?: string; arch?: string }
 export interface PushResult { name: string; ok: boolean; version?: string; error?: string }
 // What a machine is called on screen: the hostname it reports, which follows a rename within
 // a poll. The name it was added under stays its identity — the URL, its accent colour, and