fix(web): address the review round on the one-route add flow

- lifecycle-chrome's second scaffold staged its workspace under the OUTER
  scaffold's temp root, coupling two supposedly independent worlds and
  leaving the aria scrub root wrong; it now uses its own workspaceCwd.
- The direct-open path now carries the same `flowBusy` gate that disables
  the equivalent menu entry, so an occupant re-registering mid-adoption
  cannot raise a second flow.
- A composition with no directory-picker no longer opens a zero-entry
  popover on the hero anchor: with nothing to pick and nothing to add,
  the gesture shows nothing. Both behaviors gain a unit test.
- Brought three partially superseded Agent Notes current (the native
  picker, the workspace UI product flow, and the sidebar browsing split),
  cross-linked to this decision, both languages re-recorded.
- Corrected this Note's own Testing section: the shared e2e helper stages
  and adopts its directory, it does not create one in-dialog — only
  workspace-management does. Named the client-seam and CLI-README residue
  in the follow-up TODO alongside the wire branch.

packages/host/apiproxy/src/api-proxy.ts

@@ -1594,8 +1594,12 @@ export function createApiProxy(ctx: Context, defaults: ApiProxyDefaults): ApiPro
       // TODO: the create-by-name branch lost its last product consumer when
       // the Web picker collapsed onto the directory flow
       // (.agents/notes/implemented/simplification/2026-07-31-one-route-to-add-a-workspace.md).
-      // Delete it with the wire schema's `name` member, this `defaults.workspaceRoot`,
-      // and the `dsh web --workspace-root` flag that exists only to feed it.
+      // Delete it with the wire schema's `name` member, this
+      // `defaults.workspaceRoot`, the client seam that carried the name
+      // (`WorkspaceCreateInput`, `WorkspacesService.create`'s `{ name }` arm,
+      // `intentName`'s name branch, the manager's "name under workspaceRoot"
+      // contract), and the `dsh web --workspace-root` flag plus its apps/cli
+      // README lines, which exist only to feed it.
       async create(request) {
         const { payload } = request
         let path: string