Code-duplication refactoring notes (draft, for discussion)

[damienmeur]

Hi Fred — while trying out a new static-analysis tool (argot, which just got Object Pascal support) on StrumPract, it surfaced a handful of copy-pasted routines in the app's own forms (the vendored use/ trees — MSEgui, uos, OvoTag, BGRABitmap — were excluded). I hand-verified each one and wrote them up in REFACTORING-NOTES.md (this PR's only change).

This is a draft / discussion PR — it changes no code, just documents the duplication with exact locations so a future fix only has to be made once. Several past commits (center-dialog, dock layout, EQ tweaks) had to be repeated across copies, which is the pattern these would remove.

Highlights (full list + line numbers in the file):

• onmouseev / onmouseevw are byte-identical — songplayer.pas:3722 vs waveform.pas:418 (same 20-line waveform mouse handler, only the name differs).
• onsetvalvol duplicated verbatim — recorder.pas:1000 vs songplayer.pas:3250 (~68 lines).
• The dock-refresh block is pasted into 13 forms (the mainfo.basedock … updatelayoutpan loop in every visiblechangeev) → one refreshdocklayouts(parentwidget) helper.
• The 10-band EQ table + its record are duplicated in recorder.pas and songplayer.pas.
• Plus paintslider (×2), an ontextedit/show-hint block (~18×), updatelayoutstrum/updatelayoutpan, InitDrawLive, RoundMath (×3 units), and an fptimer vs msetimer consistency nit.

I didn't include the actual refactors because I couldn't compile-test them here — happy to send compile-tested commits for any of these on request, starting with the four cleanest (the two identical handlers, the dock-refresh helper, the shared EQ table). Just let me know which you'd want, or feel free to take the notes and run with them.

🤖 Generated with Claude Code

[fredvs]

Hello Damien.
Sorry about the delay, I am a few out of the game for the moment.
I will check your pull request asap.
Many thanks for this.

Fred