Header dot: don't go red on machine switch; reflect remote reachability

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

web/src/Shell.tsx

@@ -75,7 +75,7 @@ export default function Shell({ me: hubMe, onLoggedOut }: { me: Me; onLoggedOut:
   // Switching machines: reset everything that belongs to a host, then re-fetch its identity.
   const switchMachine = (name: string | null) => {
     setMachine(name); sessionStorage.setItem('hamlab.machine', name ?? ''); if (!name) sessionStorage.removeItem('hamlab.machine')
-    handles.current = {}; setTerms([]); setActive(null); setRemoteMe(null); setRemoteErr(''); setDrawer(false)
+    handles.current = {}; setTerms([]); setActive(null); setRemoteMe(null); setRemoteErr(''); setDrawer(false); setOnline(true)
     setMachineState(name)
     if (view === 'machines') setView('dashboard')
   }
@@ -136,7 +136,7 @@ export default function Shell({ me: hubMe, onLoggedOut }: { me: Me; onLoggedOut:
         {machine && remoteErr && <span className="badge bad" title={remoteErr}>offline</span>}
         <span className="spacer" />
         <span className="stat" title="load average">{me.load}</span>
-        <span className={'dot ' + (online ? 'ok' : 'bad')} title={online ? 'connected' : 'disconnected'} />
+        <span className={'dot ' + (online && !remoteErr ? 'ok' : 'bad')} title={remoteErr ? `${machine} unreachable` : online ? 'connected' : 'disconnected'} />
         <Power host={me.host} rebootNeeded={me.reboot_needed} />
         <Btn className="link" onClick={logout}>logout</Btn>
       </header>