fix(kon): spinner direction, sidebar nav lock, rebrand to Kon

- Spinner: reversed sinhala-spin from counter-clockwise to clockwise
- Sidebar nav lock: removed {#key page.current} block that forced full
  destroy/recreate of pages on every navigation. DictationPage's AudioWorklet
  cleanup in onDestroy was blocking the UI during the {#key} destruction cycle.
  Now uses {#if} blocks only — smoother page transitions.
- Rebranded sidebar: Ramble → Kon, v0.2 → v1.0

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/app.css

@@ -275,7 +275,7 @@ html.light .animate-glow-pulse {
 /* Sinhala character spin (decorative, during recording) */
 @keyframes sinhala-spin {
   from { transform: rotate(0deg); }
-  to { transform: rotate(-360deg); }
+  to { transform: rotate(360deg); }
 }
 .animate-sinhala-spin {
   animation: sinhala-spin 2s linear infinite;