fix(practice): prevent decomposition math from wrapping

Add whiteSpace: 'nowrap' to keep the step-by-step math on one line.

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

apps/web/src/components/practice/ActiveSession.tsx

@@ -931,6 +931,7 @@ export function ActiveSession({
                   borderRadius: '8px',
                   border: '1px solid',
                   borderColor: isDark ? 'blue.800' : 'blue.100',
+                  whiteSpace: 'nowrap',
                 })}
               >
                 <div