feat(orbit): replace topbar trigger label with custom wordmark SVG

Inline SVG component using currentColor so the wordmark inherits the
button's accent tint and hover state. Hover rotation is now scoped to
the lucide spinner icon so the wordmark doesn't tilt with it.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/components/OrbitStartTrigger.tsx

@@ -7,6 +7,7 @@ import { useAuthStore } from '../store/authStore';
 import { useHelpModalStore } from '../store/helpModalStore';
 import OrbitStartModal from './OrbitStartModal';
 import OrbitJoinModal from './OrbitJoinModal';
+import OrbitWordmark from './OrbitWordmark';
 
 /**
  * Topbar trigger — opens a small launch popover offering three choices:
@@ -71,10 +72,11 @@ export default function OrbitStartTrigger() {
         data-tooltip-pos="bottom"
         aria-haspopup="menu"
         aria-expanded={popoverOpen || undefined}
+        aria-label={t('orbit.triggerLabel')}
         style={{ position: 'relative', display: 'flex', alignItems: 'center', gap: '0.5rem', padding: '0.5rem 1rem' }}
       >
-        <OrbitIcon size={18} />
-        <span>{t('orbit.triggerLabel')}</span>
+        <OrbitIcon size={18} className="orbit-start-trigger__spin" />
+        <OrbitWordmark height={14} />
       </button>
 
       {popoverOpen && createPortal(