AetherClaude contribution — applies the two legit alignment fixes from
#1694 and skips the SMOOTH_ALPHA tuning change which is a UX decision.

- Waterfall bin index uses pixel-center sampling
  ((x + 0.5) * bins / destWidth) so the same frequency lands on the
  same x coordinate in spectrum and waterfall.  Previously a half-bin
  offset drifted the two panes.
- Spectrum x-coord uses \`i / (n - 1)\` so the last sample lands exactly
  at the right edge instead of one pixel short.
- Empty-data guard loosened from \`isEmpty()\` to \`size() < 2\` so
  single-point transient states don't try to draw a line segment.

Scope deliberately narrowed: the original PR also bumped
SMOOTH_ALPHA 0.35 → 0.50 as a perceived-lag improvement; that's a
user-facing rendering tuning change that needs maintainer sign-off
and is better reviewed independently from the alignment bug fix.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

)

Cuts a community-contribution-heavy point release.  Ten community PRs
landed plus an AetherClaude bug-fix batch covering TCI duplicate-stream
/ no-RF, PC Audio button sync, zoom full-BW, VFO edge jitter, audio pan
with NR, per-slice AF mute persistence, waterfall passband shading,
filter-edge jitter, NR2 crackling, rigctld Windows IPv4, DX cluster
reconnect, serial port persistence, compression meter gain reduction,
macOS audio device override, and bandwidth-correction echo guard.

Highlights for the release notes:
- macOS MNR (MMSE-Wiener spectral NR) with Accelerate/AMX acceleration
- Quick memory browse / save actions on slice overlays (jensenpat)
- Improved TNF notch interaction with bidirectional drag (rfoust)
- RAC Canada band plan expanded to VHF/UHF + 60 m ISED update (VE3NEM)
- Low-Latency DAX toggle consolidated into RADE mode
- View → Frameless Window toggle (Ctrl+Shift+F)

The #1694 spectrum/waterfall alignment attempt was landed partially
then reverted when it made alignment worse instead of better — net
zero, noted in the CHANGELOG "Reverted" section.  Issue #1690 closed
as not-a-bug.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>