* work on basic sidebar layout
* fix more golang warnings
* sidebar open/close
* add ability to set width of split
* sidebar add and remove, set width, etc.
* almost working sidebar implementation -- still needs height/width, input control, and bug with initial add, but getting there
* add isSidebarOpen() method
* fix resize jump -- must set width in error handler as well (before window is loaded)
* sidebar UI touchups and help
* more sidebar progress, render more like regular lines, just in the right column
* merge
* move migration to 26
* simplify sidebar types
* checkpoint
* proxy things through parent screen object for sidebar
* checkpoint, add/remove from sidebar
* work on add/remove icons for sidebar
* fix height calculation, remove close button
* bring back close button when no line is selected
* add sidebar flag to run command to run new command output in sidebar
* implement 'sidebar' kwarg in eval. this lets sidebar work for slashcommands as well that produce lines (codeedit, mdview, etc.)
* prettier
* minor fixes
* working on resizing. must exclude sidebar entries and send separate resize events based on size of sidebar (implement exclude / include for resize)
* fix sidebar terminal command resizing
* add sidebar header (toggles for half/partial width and close). add hotkey to open/close sidebar (Cmd-Ctrl-S). more robust calculation for sidebar width. add width validation. minimum sidebar width is 200px. other fixes, etc.
