Reject unreasonable WAV header values

[Mirochill]

Summary

Reject WAV files with unreasonable header metadata before returning an AudioSegment.

Fixes #877.

Changes

• Adds bounds checks for WAV channel count, sample rate, and bit depth in read_wav_audio().
• Keeps existing 64-bit WAV support while rejecting extreme values such as 100MHz sample rates, 65k channels, or 65k-bit samples.
• Adds regression coverage using synthetic WAV headers for each invalid metadata field.

Validation

Not run locally.

Static validation performed:

• git diff --check