Display Scale: clarify applet versus extension for panel compensation

[randomkiapps]

Hello Cinnamon Spices maintainers,

I would like to submit Display Scale, a Cinnamon panel control for making
desktop content easier to read from a greater viewing distance. Before preparing
the final pull request, I would appreciate your guidance on one architectural
point.

The control has a compact vertical slider from 100% to 200% and two mutually
exclusive buttons:

• Text and layout: changes Cinnamon's text scaling factor; individual
  applications decide how they respond.
• Entire screen: uses an asynchronous XRandR helper to enlarge the output
  while retaining the physical display mode. Interpolation can soften the image.

The slider supports 5, 10 or 25 percentage-point steps, or up to three custom
intermediate stops. An optional panel compensation keeps panel dimensions,
icons and text approximately at their original apparent size. Panel text can
optionally grow with the rest of the desktop. Multiple panels on the same
monitor are handled.

This panel compensation currently uses reversible runtime replacements of:

• Panel instance methods _getScaledPanelHeight,
  _clampPanelZoneColorIconSize and _clampPanelZoneSymbolicIconSize.
• The grouped window list's getPreferredWidth and getPreferredHeight
  prototype methods, to prevent overlapping icons under output zoom.

It also applies temporary font styles and actor properties. System source files
are not modified; the temporary changes are cleaned up when compensation stops
or the applet is removed. This describes the implementation, rather than an
exemption from the rule.

I have read the repository's review instructions prohibiting applets from
overriding core Cinnamon behavior. Would you require this functionality to be
implemented as an extension, possibly with an applet as its control, or is
there an approved API or other approach that would allow the panel compensation
to remain in an applet? Preserving the panel is an important part of the use case.

The development version has been tested interactively on LMDE 7, Cinnamon
6.6.9, X11, Intel N100. Screen mode currently supports one active, unrotated
monitor without an existing unrelated output transformation. Multi-monitor
screen scaling and Wayland are not claimed as supported. This is a development
version, not yet a general release.

The text-scaling starting point was a modified uiscaler@joka42; attribution
to joka42 and the earlier Resolution Switcher by dennis@nixdev.com is retained.
The development was AI-assisted and includes automated interaction checks in
addition to the desktop testing.

Thank you for advising on the appropriate packaging before I submit the code.

[mtwebster]

Feel free to submit it as a third-party spice, but we're not interested in this in core Cinnamon. I wouldn't put any additional effort in to fractional scaling using xrandr beyond what's already available thru Cinnamon's display settings - it's resource-intensive and buggy/useless on a lot of hardware.

Also, there's already an accessibility applet that lets you toggle larger text.