feat: rebuild workspaces as the reference plugin

plugins/workspaces/CHANGELOG.md

@@ -3,3 +3,13 @@
 ## 1.0.0
 
 Bundled with Termix 2.9.0.
+
+- Owns its data: core's `user_workspaces` table is renamed to
+  `p_workspaces_workspaces` on first activation, keeping every saved workspace.
+- New `workspaces.use` permission, given to the admin and user roles. Without
+  it the rail item is hidden and the routes answer 403.
+- Saved workspaces sync between the desktop app and a server. The per-device
+  "Last Session" does not.
+- Offers `workspaces.saved` to other plugins, used by the AI assistant.
+- A tab from a plugin that is off is kept as a placeholder when a workspace is
+  applied, instead of being dropped.