feat: simplify account create/edit and add row copy

Data-management add/edit now use short forms with enums; copy clones a platform account into a new empty profile.

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/test_usage.py

@@ -27,6 +27,8 @@ def test_usage_includes_all_account_subcommands():
         "init-master-key",
         "export-credentials",
         "import-credentials",
+        "copy",
+        "update",
         "add-web",
         "ensure-web",
         "get-credential",