fix(levels): increase animation speed to 10ms for 10th Dan

Update animation speed progression to be more dramatic, reaching 10ms
(0.01 seconds) at 10th Dan instead of 50ms. Speed progression now runs
from 1st Dan to 10th Dan (not from Pre-1st Dan).

Speed progression:
- Kyu levels: 500ms (constant)
- Pre-1st Dan: 500ms
- 1st Dan: 500ms
- 10th Dan: 10ms
- Linear interpolation between 1st and 10th Dan

This creates an extremely fast blur effect at the highest mastery level,
better representing the extraordinary calculation speed expected at 10th Dan.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

apps/web/src/app/levels/page.tsx

@@ -202,17 +202,18 @@ export default function LevelsPage() {
   useEffect(() => {
     // Calculate animation speed based on level
     // Kyu levels: 500ms
-    // Dan levels: interpolate from 500ms (Pre-1st Dan) to 50ms (10th Dan)
+    // Pre-1st Dan: 500ms
+    // 1st-10th Dan: interpolate from 500ms to 10ms
     const getAnimationInterval = () => {
-      if (currentIndex < 10) {
-        // Kyu levels: constant 500ms
+      if (currentIndex < 11) {
+        // Kyu levels and Pre-1st Dan: constant 500ms
         return 500
       }
-      // Dan levels: speed up from 500ms to 50ms
-      // Index 10 (Pre-1st Dan) → 500ms
-      // Index 20 (10th Dan) → 50ms
-      const danProgress = (currentIndex - 10) / 10 // 0.0 to 1.0
-      return 500 - danProgress * 450 // 500ms down to 50ms
+      // 1st Dan through 10th Dan: speed up from 500ms to 10ms
+      // Index 11 (1st Dan) → 500ms
+      // Index 20 (10th Dan) → 10ms
+      const danProgress = (currentIndex - 11) / 9 // 0.0 to 1.0
+      return 500 - danProgress * 490 // 500ms down to 10ms
     }
 
     const intervalMs = getAnimationInterval()