fix: aliasing in sinc downsampling

[roderickvd]

Add rate-dependent configuration to Interpolator and use it in Sinc to apply an anti-aliasing bandwidth when downsampling. The Interpolator trait now exposes set_hz_to_hz, set_playback_hz_scale, and set_sample_hz_scale (default no-ops). The Converter methods call them automatically, without API breakage.

Fixes #174

[Copilot]

Pull request overview

This PR fixes aliasing issues in the Sinc interpolator during downsampling by introducing rate-dependent configuration. The changes allow the Sinc interpolator to automatically adjust its anti-aliasing bandwidth based on the sample rate conversion ratio.

Changes:

• Extended the Interpolator trait with three rate configuration methods (set_hz_to_hz, set_playback_hz_scale, set_sample_hz_scale) with default no-op implementations
• Modified the Sinc interpolator to store and apply a bandwidth parameter for anti-aliasing
• Updated Converter methods to automatically configure interpolators with rate information
• Added a test to verify anti-aliasing works correctly during downsampling

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
dasp_interpolate/src/lib.rs	Added rate configuration methods to the Interpolator trait with comprehensive documentation
dasp_interpolate/src/sinc/mod.rs	Added bandwidth field and implemented rate configuration methods to apply anti-aliasing
dasp_signal/src/interpolate.rs	Modified from_hz_to_hz constructor and setter methods to call interpolator rate configuration
dasp_signal/tests/interpolate.rs	Added test verifying anti-aliasing filters out frequencies above Nyquist during downsampling
CHANGELOG.md	Documented the changes and additions to the API

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[roderickvd]

Converted to draft: spectrogram reveals that it's got some issues.

[roderickvd]

There, that should be better.