refactor: drop the create-by-name workspace route

The Web picker collapsed onto the directory flow (see the one-route-to-add-a-workspace
Agent Note), leaving workspace.create({ name }) with no product consumer. Delete the
whole feed line: the wire schema's name member and WorkspaceApi spelling, the gateway's
workspaceRoot config/default and the mkdir branch, the client seam that carried the name
(WorkspaceCreateInput, WorkspacesService.create, intentName), the dsh web
--workspace-root flag, and the fixture's name handling. workspace-name-conflict stays as
workspace.rename's duplicate-title error.

packages/bundle/web-app/cordis.patch.yml

@@ -4,7 +4,7 @@
 #
 # A patch replaces the targeted row's whole `config`, so each row below
 # restates every key it owns. The `dsh web` launcher alias turns --host/--port/
-# --dev/--workspace-root/--trusted-host into further patches over these rows
+# --dev/--trusted-host into further patches over these rows
 # (`--dev` inserts the dsh-client-hmr row).
 
 # ── surface-specific values the base deliberately omits ─────────────────────