fix: calculate WPM based on correctly typed words in Typing Speed Tester

WPM was calculated using the original sentence word count, giving
inflated results when the user typed fewer or different words.
Now counts only correctly typed words (net WPM) for an accurate metric.

Fixes steam-bell-92#898

Author: nyxsky404

utilities/Typing-Speed-Tester/Typing-Speed-Tester.py

@@ -70,9 +70,14 @@
     # Calculate time
     time_taken = end_time - start_time
 
-    # Calculate words per minute
-    words = len(sentence.split())
-    wpm = (words / time_taken) * 60 if time_taken > 0 else 0
+    # Calculate words per minute based on typed text
+    sentence_words = sentence.split()
+    typed_words = typed_text.split()
+    correct_words = sum(
+        1 for i, word in enumerate(typed_words)
+        if i < len(sentence_words) and word == sentence_words[i]
+    )
+    wpm = (correct_words / time_taken) * 60 if time_taken > 0 else 0
 
     # Calculate accuracy
     correct_chars = 0