Add MP3 overlap detection utility

[Copilot]

Two MP3 recordings need automated overlap detection with timestamped results for each source.

• Audio decoding: Converts both MP3 inputs to mono PCM through ffmpeg.
• Alignment: Uses NumPy FFT cross-correlation to identify shared audio.
• Segmentation: Groups matching frames into contiguous overlap intervals.
• Reporting: Prints readable start/end timestamps for both recordings.

python3 data_preparation/overlap_detection/detect_overlap.py recording1.mp3 recording2.mp3

[michnov]

@copilot what if we assume that one recording is just entirely included in the other one. Would the calculation change and is it higher chance to get the times of the entire contiguous segment, not just tens of non-contiguous segments?

[Copilot]

@copilot what if we assume that one recording is just entirely included in the other one. Would the calculation change and is it higher chance to get the times of the entire contiguous se...

Implemented a --mode contained switch. It searches for the shorter recording inside the longer one using normalized sliding correlation and reports one contiguous interval, while --mode general preserves the original behavior. Changes are in ea96353 (with the finalization commit 6c66a55).