FAD: The good old click-less fractionally addressed delay

[kunitoki]

Adds a new Fractional Delay audio graph node powered by a DSP-level Fractionally Addressed Delay (FAD) implementation, along with state serialization support for existing nodes.

Changes

• Added yup::FractionallyAddressedDelay to yup_dsp.
  • Fractionally-addressed delay line based on Rocchesso's FAD architecture
  • Supports fractional delay lengths, block/in-place processing, and delay modulation
  • Comprehensive unit test coverage
• Added Fractional Delay node to the AudioGraph example
  • Independent left/right delay times
  • Feedback and Dry/Wet controls
  • Node state persistence
  • Integrated into the node registry and palette
• Added state serialization/deserialization for:
  • Oscillator node
  • Gain node
  • Low-pass filter node
  • Updated NodeViewHelpers to support multiple inline parameter rows, enabling richer node UIs.

This provides a new modulation-friendly delay primitive in yup_dsp and demonstrates its use through a fully functional AudioGraph node.

[codecov]

Codecov Report

❌ Patch coverage is 86.81948% with 46 lines in your changes missing coverage. Please review.
✅ Project coverage is 77.13%. Comparing base (8854a46) to head (3897654).

Files with missing lines	Patch %	Lines
...audio_processors/processors/yup_AudioProcessor.cpp	51.16%	21 Missing ⚠️
...ules/yup_gui/themes/theme_v1/yup_ThemeVersion1.cpp	0.00%	15 Missing ⚠️
...ules/yup_audio_graph/graph/yup_AudioGraphModel.cpp	86.36%	6 Missing ⚠️
modules/yup_dsp/nonlinear/yup_AaIirAntialiaser.h	98.36%	3 Missing ⚠️
...es/yup_dsp/delays/yup_FractionallyAddressedDelay.h	98.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #109      +/-   ##
==========================================
+ Coverage   77.04%   77.13%   +0.08%     
==========================================
  Files         602      605       +3     
  Lines       60147    60483     +336     
==========================================
+ Hits        46340    46651     +311     
- Misses      13807    13832      +25     

Files with missing lines	Coverage Δ
...odules/yup_audio_graph/graph/yup_AudioGraphModel.h	66.66% <ø> (ø)
.../yup_audio_graph/graph/yup_AudioGraphProcessor.cpp	94.78% <100.00%> (ø)
...les/yup_audio_processors/processors/yup_AudioBus.h	100.00% <ø> (ø)
...p_audio_processors/processors/yup_AudioProcessor.h	83.78% <100.00%> (+2.70%)	⬆️
modules/yup_dsp/dynamics/yup_HardClipper.h	100.00% <100.00%> (ø)
...es/yup_dsp/delays/yup_FractionallyAddressedDelay.h	98.00% <98.00%> (ø)
modules/yup_dsp/nonlinear/yup_AaIirAntialiaser.h	98.36% <98.36%> (ø)
...ules/yup_audio_graph/graph/yup_AudioGraphModel.cpp	93.58% <86.36%> (-0.71%)	⬇️
...ules/yup_gui/themes/theme_v1/yup_ThemeVersion1.cpp	37.91% <0.00%> (-0.46%)	⬇️
...audio_processors/processors/yup_AudioProcessor.cpp	74.56% <51.16%> (-14.18%)	⬇️

... and 3 files with indirect coverage changes

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