Stop false warnings on panel values
A phase that filled its panel with setattr or through a helper got one wrong warning per value, which could bury real problems under hundreds of lines.
- Fixed the "never writes" warning: it no longer fires when a phase writes panel values with
setattr(ui, ...)or passesuito a helper. - Improved validation on generated panels: the panels gallery examples went from 1858 of these warnings to none.
- Updated the panels documentation to say when the check cannot follow a write.
