## Summary

`omarchy-menu-keybindings` (`SUPER + K`) builds a Lua bind cache by `dofile`ing `~/.config/hypr/hyprland.lua` against a stub `hl`. That stub’s self-referential noop makes `ipairs(hl.get_windows())` never terminate, so any Hyprland toggle/plugin that iterates windows at load time wedges the cheatsheet at ~100% CPU until kill/restart.

Reproduced with [duncio/omarchy-cava](https://github.com/duncio/omarchy-cava) (backdrop visualizer that recovers its window via `ipairs(hl.get_windows())` on load). Same class of bug will hit any future toggle that does the same.

## Environment

- Omarchy 4.0.4-1
- Hyprland 0.56.2
- `omarchy-menu-keybindings` from packaged `/usr/share/omarchy/bin/omarchy-menu-keybindings`

## Steps to reproduce

1. Install a Hyprland toggle that runs `ipairs(hl.get_windows())` at load (e.g. enable `io.github.duncio.omarchy-cava`, which installs `~/.local/state/omarchy/toggles/hypr/omarchy-cava.lua`).
2. Run `omarchy-menu-keybindings --print` or press `SUPER + K`.

## Expected

Bind list prints / cheatsheet opens quickly.

## Actual

`lua` child spins at ~100% CPU forever; cheatsheet never appears. Process tree looks like:

`omarchy-menu-keybindings` → `lua` (R, ~100% CPU)

## Root cause

In `build_lua_bind_cache`, the stub is effectively:

```lua
noop = setmetatable({}, {
  __index = function() return noop end,
  __call = function() return noop end,
})
-- hl.get_windows → noop via __index; noop() → noop via __call
```

Lua 5.4 `ipairs` uses `__index` and stops only on `nil`. So `ipairs(noop)` yields forever.

The hang is during `require("default.hypr.toggles")` after bind lines have already been printed.

The same pattern exists in third-party scanners (e.g. keymap plugin `scripts/scan.lua`).

## Suggested fix (Omarchy)

Make the scanner noop safe for `ipairs` / `#`:

```lua
noop = setmetatable({}, {
  __index = function(_, key)
    if type(key) == "number" then return nil end
    return noop
  end,
  __call = function() return noop end,
  __len = function() return 0 end,
})
```

Optionally also set an env like `OMARCHY_KEYMAP_SCAN=1` (keymap already honors this) so toggles can skip live bookkeeping intentionally.

## Related

Plugin-side report: will link to `duncio/omarchy-cava` issue after create.

Diagnostic log locally: `/tmp/omarchy-debug.log` (from `omarchy-debug --no-sudo --print`).