### What happened

Opening the keybindings menu (SUPER+K) spawns a `lua` process that never
exits and pins one CPU core at ~100% indefinitely. Every SUPER+K press
(when the keybindings cache misses) spawns another one, so repeated
presses stack up multiple runaway processes.

### Root cause

`omarchy-menu-keybindings`'s `build_lua_bind_cache()` runs a `lua` heredoc
that `dofile()`s the user's `~/.config/hypr/hyprland.lua` chain against a
mocked `hl` table, to discover Lua-registered binds without actually
talking to Hyprland. The mock's fallback object is:

```lua
local noop
noop = setmetatable({}, {
  __index = function()
    return noop
  end,
  __call = function()
    return noop
  end,
})
```

Any `hl.*` field not explicitly stubbed (only `dsp`, `bind`, and
`get_config` are) resolves through `__index` to `noop`, and calling it
also returns `noop` — always truthy, never `nil`.

My `~/.config/hypr/monitors.lua` (an ordinary, working config used to
pick a monitor layout based on which dock is connected) contains:

```lua
for _, m in ipairs(hl.get_monitors()) do
```

Under real Hyprland this is fine. Under the mock, `hl.get_monitors()`
returns `noop`, and `ipairs(noop)` walks `noop[1]`, `noop[2]`, `noop[3]`, …
via `__index` — which never returns `nil` — so the loop never terminates.

This isn't specific to `get_monitors`: any config that calls an
un-stubbed `hl.*` function and iterates its result with `ipairs`/`pairs`
will hang the same way.

### Expected

The keybindings menu's background scan should either finish quickly or
fail safely, without ever spinning a CPU core forever.

### Steps to reproduce

1. In `~/.config/hypr/monitors.lua` (or any file in the `hyprland.lua`
   require chain), add:
   `for _, m in ipairs(hl.get_monitors()) do end`
2. Press SUPER+K (or run `omarchy-menu-keybindings`) once the keybindings
   cache is stale/empty.
3. Observe a `lua` child process (parent: `omarchy-menu-keybindings`)
   pinned at ~100% CPU that never exits.

### Suggested fix

Make the mock's numeric indexing terminate instead of looping forever,
e.g.:

```lua
__index = function(_, key)
  if type(key) == "number" then return nil end
  return noop
end,
```

This lets `ipairs()` over any un-stubbed `hl.*` return value stop after
zero iterations, while leaving string-keyed chaining (`hl.dsp.exec_cmd`,
etc.) untouched.

### System

- Omarchy version: 4.0.1-1
- Reproduced via a real user config, not a synthetic minimal case

Filed by Claude Sonnet 5 via Claude Code.