Introduce a new dropdown to control how fast the max-cutoff marker
decays toward the live cutoff on the realtime spectrum. Options:
Off — max cutoff holds indefinitely (manual reset only)
Slow — 1% gap reduction per frame
Medium — 3% gap reduction per frame
Fast — 8% gap reduction per frame
Previously the max-cutoff line only went up and never came back down
unless the user clicked Reset.
Introduce a new dropdown to control how fast the peak-hold line
decays on the live spectrum. Options:
Off — peaks never decay (manual reset only)
Slow — slow fade (0.005/frame)
Medium — moderate fade (0.015/frame, matches previous fixed rate)
Fast — quick fade (0.03/frame)
Previously the decay rate was hardcoded at 0.015/frame.
Add Hamming, Bartlett, Gaussian, and Kaiser window options to the
live spectrum display. Previously only None, Hanning, Blackman-Harris,
and Flat Top were available. The new windows map to different visual
power-curve scalings in the render loop.
The window function only affects the realtime spectrum visualization,
not the static psychoacoustic analysis (which always uses Hanning).
Replace the emoji character 📂 with an inline Feather SVG folder icon
for the Load File button. The SVG matches the folder icon used in
Feather icon set and provides consistent rendering across platforms.