Archive any workspace from the app (#2003)

* feat(app): expose archive for every workspace

Workspace actions now archive one workspace by id. The daemon remains responsible for backing-specific cleanup, including removing a managed worktree only after its final workspace is archived.

* refactor(app): clarify archive descriptor name

* fix(app): preserve workspace archive safety

* fix(app): allow archive without upstream

* refactor(app): remove stale archive callback

* test(app): cover workspace archive ownership

packages/app/src/keyboard/route-shortcut.test.ts

@@ -30,7 +30,7 @@ describe("routeKeyboardShortcut — dispatch passthroughs", () => {
     ["agent.interrupt", { id: "agent.interrupt", scope: "global" }],
     ["workspace.tab.new", { id: "workspace.tab.new", scope: "workspace" }],
     ["workspace.new", { id: "workspace.new", scope: "sidebar" }],
-    ["worktree.archive", { id: "worktree.archive", scope: "sidebar" }],
+    ["workspace.archive", { id: "workspace.archive", scope: "sidebar" }],
     ["worktree.new", { id: "worktree.new", scope: "sidebar" }],
     ["workspace.terminal.new", { id: "workspace.terminal.new", scope: "workspace" }],
     ["workspace.tab.close.current", { id: "workspace.tab.close-current", scope: "workspace" }],