## Repurpose `SUPER + W` for tab/view close now that `SUPER + Q` also closes windows

### Summary

On `quattro`, `default/hypr/bindings/tiling.lua` binds **both** `SUPER + W` and
`SUPER + Q` to "Close window" (`hl.dsp.window.close()`):

```lua
o.bind("SUPER + W", "Close window", hl.dsp.window.close())
o.bind("SUPER + Q", "Close window", hl.dsp.window.close())
```

Since `SUPER + Q` now covers the "quit / kill window" role (matching macOS `⌘Q`
and i3/sway's `SUPER + SHIFT + Q` muscle memory), `SUPER + W` is redundant. It
could instead take the role its macOS counterpart `⌘W` has: **close the current
tab / view inside the focused app**.

### Motivation

Omarchy has adopted the macOS mental model where SUPER is the app-level modifier
— `SUPER + C / V / X` are mapped to universal copy/paste/cut in
`bindings/clipboard.lua` by forwarding the `CTRL` equivalent to the focused
surface. `SUPER + W` mapping to `killactive` is the odd one out: on macOS `⌘W`
closes a *tab/document*, not the app.

This is most obvious in the browser, where closing a tab is `Ctrl + W` — so the
key muscle memory says "close this tab" instead kills the whole window.

### Proposal

Bind `SUPER + W` to forward `CTRL + W` to the focused surface, mirroring the
`SUPER + C / V / X` pattern already in `bindings/clipboard.lua`
(`send_shortcut_once`, and the per-app branching in
`universal_clipboard_shortcut`). `Ctrl + W` is already "close tab / close view"
in browsers, editors, file managers, tmux, etc. `SUPER + Q` stays as the
window/app kill.

### Trade-offs / open questions

- **Breaking change.** `SUPER + W` = kill window is deeply ingrained; this needs
  a migration note and possibly a deprecation period.
- **`Ctrl + W` is not universally "close".** In many GTK text entries and
  readline/emacs-style contexts it means "delete previous word". A blanket
  forward would delete a word instead of closing a tab in those apps, so this
  inherits the same per-app special-casing burden `clipboard.lua` already
  carries (e.g. its terminal `Ctrl+Insert` / `Shift+Insert` branch). A
  conservative alternative: only forward for a known set of tags (browser,
  editor, terminal), and leave `SUPER + W` unbound elsewhere.
- **Single-view GUI apps** have no "close current view" concept, so `SUPER + W`
  would do nothing there — users fall back to `SUPER + Q`. Arguably expected.
- **Last tab in a browser:** `Ctrl + W` on the final tab closes the window, so
  behaviour stays sensible at the boundary.

### Fallback ask

If forwarding is deemed too fragile, simply **unbind `SUPER + W`** (keep
`SUPER + Q` as the sole "Close window") so the key is free for users to remap
and no longer shadows an app's own `Ctrl + W` expectations.

### Environment

- Branch: `quattro`
- `default/hypr/bindings/tiling.lua` lines 1–2
- Forwarding precedent: `default/hypr/bindings/clipboard.lua`