- New unit SpectrumView.pas (TSpectrumView): encapsulates all
spectrum, waterfall, ruler and S-meter rendering; ~900 lines
removed from MainForm.pas
- Fix marker bug: FMarkerActive/FMarkerX were duplicated in
MainForm and TSpectrumView — mouse handlers now write directly
to FSpecView, stale MainForm fields removed
- Fix filter band and ruler not following VFO: add SyncSpecViewFreq
helper called at every draw site and at top of SpectrumTimerTick
- Remove dead code: WFALL_PALETTE (34 lines), FSplitter, LblAGC,
LblVol, WinFirewall/IntfGraphics/FPImage from uses
- Fix pre-existing bug: SidetoneFreqLo := 600 overflowed Byte,
replaced with Hi(600)/Lo(600)
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>