Area Switcher by aldk

Four workspaces (1, 2, 3, A) separate visible tab sets in each Firefox window. Pinned tabs stay visible everywhere. The toolbar button opens a tab overview: every tab of the window grouped by workspace; a click goes to the tab and switches workspace on the way, × closes it (shortcut Ctrl+Shift+5). X adds a PIN visibility gate and a red Firefox tab group; while X is locked the overview shows only how many tabs it holds. X is a visibility aid, not encryption or access control; all workspaces share cookies and logins. Place the edge rail on either side or disable it. No telemetry, advertising, accounts or transmission to the developer. Private windows are not supported. Empty base workspaces open Google; X uses a local start page. The default X visibility PIN is 1 and can be changed in the popup. Websites can observe PIN keystrokes entered in the rail.