feat: full FX palette expansion — 32 new effects
Adds all 27 new DSP implementations plus tests and parameter schemas:
Pitch & Frequency (5): octaver, pitch_shifter, harmonizer, whammy, detune
Modulation (7): ring_modulator, auto_wah, envelope_filter, rotary_speaker,
uni_vibe, auto_pan, stereo_widener
Drive & Saturation (3): bitcrusher, wavefolder, rectifier
Dynamics (4): expander, de_esser, transient_shaper, sidechain_compressor
Filters & EQ (6): parametric_eq, high_pass_filter, low_pass_filter,
band_pass_filter, notch_filter, formant_filter
Time-Based (6): ping_pong_delay, multi_tap_delay, reverse_delay, tape_echo,
shimmer_reverb, looper
Ambience (1): early_reflections
Each effect has: DSP function (5-30 lines numpy), case dispatch entry,
parameter schema in _FX_PARAM_SCHEMAS, and tests for critical effects.
CPU-heavy effects (pitch_shifter, shimmer_reverb) tagged as BETA.
All 79 tests pass.
shawn
c8d7541065