fix: Increase tutorial annotation label size for readability

Reduced distanceFactor from 10 to 6 and increased text from text-sm
to text-base so labels near Earth are easier to read.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: cjw6k

tidal-harmonics/src/components/tutorial/AnnotationLayer.tsx

@@ -17,15 +17,15 @@ export function AnnotationLayer() {
           key={annotation.id}
           position={annotation.position}
           center
-          distanceFactor={10}
+          distanceFactor={6}
           occlude={false}
           style={{
             pointerEvents: 'none',
             userSelect: 'none',
           }}
         >
           <div
-            className={`px-3 py-1.5 rounded-lg text-sm whitespace-nowrap
+            className={`px-3 py-2 rounded-lg text-base whitespace-nowrap
               ${
                 annotation.style === 'highlight'
                   ? 'bg-blue-600 text-white font-medium'