Strip the bash-bin compatibility layer from Menu.qml

With bin/omarchy-menu gone there's no caller that summons the menu by
writing a JSON tempfile and polling a done file. Drop everything that
existed only to support that handshake:

  - menuJsonFile / menuJsonFileView / loadMenuJson / openMenu(json,...)
  - pendingSelectionFile / pendingDoneFile / selectionFile / doneFile
  - mergeProviderJson (the JSON-wrapper for provider output)
  - applyProc / releaseProc / doneFilesToRelease / finishDoneFile /
    releaseNextDoneFile / resetRequest / requestActive / closeMenu
  - the menuBin property pointing at the deleted bin

applySelected is now four lines (close + execDetached); cancel is two
(close + clear filter). open() takes either {menu: id} or a bare initial
menu name, and hands off to openExistingMenu which uses the cached items
from the JSONC FileViews.

Net: 91 lines smaller, no perf change.

config/omarchy/extensions/omarchy-menu.jsonc

@@ -11,7 +11,7 @@
   //   action      Shell command to run. If omitted, the row is a submenu.
   //   target      Existing submenu id to open. Use for links/aliases.
   //   provider    Runtime provider function/command returning JSON rows.
-  //   aliases     Alternate `omarchy-menu <name>` routes; also searchable.
+  //   aliases     alternate `omarchy-shell-ipc menu summon <name>` routes; also searchable.
   //   keywords    Extra search terms beyond id/label/aliases.
   //   description Optional subtitle and extra search text.
   //   when        Shell condition; hide row when it fails.