forked from 1b-agent/opencadstudio-upstream
Restructure the plot dialog into a style-manager-style master/detail: a left list of page setups plus a right settings editor. The list shows <none> (defaults + PDF) and <previous> (the settings the dialog opened with), then the drawing's layouts (*Model*, *Layout1*, …) and its standalone named page setups. - Named page setups live in the ACAD_PLOTSETTINGS dictionary (src/scene/page_setup.rs: names/get/save/delete/rename, creating the dictionary if absent); DWG round-trip verified. - Toolbar New / Copy / Delete | Set current / Preview / Print. Selecting a row loads it into the editor; Set current writes to the active layout. Copy duplicates a layout or a setup into a new named setup; Delete/Rename apply only to named setups. - Scene::plot_settings_for(name) generalizes effective_plot_settings so any layout's settings can be loaded; on open the settings are snapshotted for <previous>. - Default selection: model space → <none>; a layout → its own setup. Co-Authored-By: Claude Opus 4.8 <[email protected]>