Check pitch threshold across full buffer

[dgruss]

• Check the pitch detection volume threshold across the full analysis buffer instead of only the first 1024 samples.
• Removes the arbitrary early-buffer limit where a valid note could be ignored if the singer was quiet only in that slice.
• Keeps the configured threshold values and pitch detection flow otherwise unchanged.
• Quiet singers may find that more fragments are picked up now.

[barbeque-squared]

inb4 we get a complaint "but this affects scoring!!!!"

well yeah duh. the last 1024 in the buffer are the newest samples so obviously it makes so much sense to determine if we need to try scoring at all by looking at the first 1024. perhaps with this change we won't miss the beginning of sentences anymore. score difference would be very minimal anyway.