v1.6.0

Added

• Vertical waveform zoom. Quiet files are auto-fitted on load (99th-percentile, so a
  single transient does not defeat it), and Alt + wheel over the waveform magnifies
  manually; 0 resets. A badge shows the factor whenever the waveform is magnified, so a
  stretched waveform is never mistaken for the file's real level. Columns the lane edge
  cut off are marked in amber.
• A dBFS amplitude ruler beside the waveform, so the Y axis reflects the magnification.
• Hover readout as a labelled box (Time / Note / Level) by default, with the previous
  single line kept as a Compact option and each field individually switchable.
• Milliseconds in the transport readout (mm:ss.mmm), on by default.
• dB² amplitude scale: half the log gain against the same contrast floor, lifting
  background detail and upper partials that the plain dB scale crushes toward black.
• Appearance setting — Follow QuickLook / Light / Dark — overriding the host's theme.
• Customizable waveform colour, with nine presets plus the theme default.
• The active frequency scale (LIN / LOG / MEL) and amplitude scale (dB / LIN /
  dB²) are shown in the plot's bottom corners, under the frequency ruler and the
  colorbar. Click either one to cycle to the next scale.

Changed

• Reverse colormap is now Never / Always / Auto (light mode only), replacing the on-off
  checkbox. The previously ticked state migrates to Always.
• The spectrogram scan no longer shifts the whole FFT window once per input sample. On a
  3-minute file this is 2.8x faster at the default FFT 1024 and 5.4x at 4096, with
  bit-identical output.
• Playhead auto-follow now works in the waveform-only view (which multichannel files open
  to) and no longer undoes a deliberate scroll on the next frame.
• Shift + wheel forces the time axis, so the timeline stays reachable over a lane stack.

Fixed

• The arrow keys switch to the previous/next file in Explorer again. The preview no
  longer takes keyboard focus away from Explorer when it opens (the first ↓ used to
  land on the volume slider). K/J/L/M/+/−/0 now work once you click the preview.
• Time-axis labels no longer pile up at the right edge. The label at the edge (e.g. 0:10
  while scrolled near the start) was pulled left onto its neighbour. Now only the file's
  final label is kept on screen, and it is dropped if it would collide.
• The play/pause button uses the same icon font as the mute and settings buttons, centred
  instead of sitting low and clipped.
• The colorbar legend no longer renders every tick as 0.00 in linear mode. The values
  are raw FFT magnitudes spanning several orders of magnitude, and a fixed two-decimal
  format collapsed them.
• Duplicate time-axis labels on short files (0:00, 0:00, 0:01, 0:01, …): the tick ladder
  bottomed out at 0.5 s while labels only ever showed whole seconds. The time ruler also
  now de-clutters overlapping labels, as the frequency ruler already did.
• The viewer follows a theme change made after the preview opens. ApplyTheme ran once
  from the constructor and nothing listened for a later change, so the palette could stick
  — usually on dark, since the OS-theme lookup falls back to dark on failure.
• Dragging on the waveform to scrub no longer re-centres the timeline under the pointer on
  every step.
• A truncated spectrogram now says so instead of silently mis-reporting every time past
  the truncation point.