## Summary

`omarchy update` (and `omarchy update -y`) exits silently and immediately with status 0, doing nothing — no free-space check output, no confirmation prompt, no package sync, and no `/tmp/omarchy-update.log` file is ever created. This happens even with `-y`, which bypasses the interactive `gum confirm` step entirely, so it isn't a TUI/terminal-capability issue with `gum`.

Reproduced on two separate machines.

## Environment

- Omarchy: 4.0.3-1
- util-linux `script`: 2.42.3
- Kernel: 7.2.3-arch1-3
- Reproduced both inside a `herdr` (0.9.0) pane and in a plain terminal outside herdr — same result in both, so herdr is not the cause.

## Steps to reproduce

```
omarchy update
```
or
```
omarchy update -y
```

## Expected

Either the confirmation prompt (without `-y`) or, with `-y`, the update proceeding straight to free-space check, package cache pruning, snapshot creation, `pacman -Syu`, etc. — as documented in `/usr/bin/omarchy-update`.

## Actual

The shell prompt returns immediately with exit code 0. No output at all. No `/tmp/omarchy-update.log` is created, even though `/usr/bin/omarchy-update` unconditionally re-execs itself through:

```bash
if [[ -z ${OMARCHY_UPDATE_LOGGED:-} ]]; then
  script_command=$(printf '%q ' "$0" "$@")
  exec env OMARCHY_UPDATE_LOGGED=1 script -qefc "$script_command" "/tmp/omarchy-update.log"
fi
```

before doing anything else. Since `script` normally creates/opens its log file immediately on start (verified independently — a plain `script -qefc 'echo hi' /tmp/test.log` works fine and produces the log), the fact that no log file appears at all suggests this `script` re-exec is failing or no-oping silently rather than anything later in the update logic being at fault.

## Workaround

Setting `OMARCHY_UPDATE_LOGGED=1` manually skips the `script`-wrapping block entirely and the update runs correctly, with full output (confirmation prompt, free-space check, pruning, snapshot, `pacman -Syu`, AUR builds, etc.):

```
OMARCHY_UPDATE_LOGGED=1 omarchy update -y
```

This strongly points to the `script -qefc ... /tmp/omarchy-update.log` re-exec itself as the broken step, rather than anything downstream in the update logic.

## Diagnostics already ruled out

- Not a stale update lock (`omarchy-update-lock held` returns false; no lock file present).
- Not a leaked `OMARCHY_UPDATE_LOGGED`/`OMARCHY_UPDATE_LOCK_FD` env var (checked, absent).
- Not disk space (`omarchy-update-requires-free-space` logic checked, well above the 10 GiB threshold).
- Not `gum`/TUI-related, since `omarchy update -y` bypasses `gum confirm` entirely and still fails identically.
- Not specific to the `herdr` terminal multiplexer — reproduced in a plain terminal outside it too.
- `script` itself works fine for trivial commands (`script -qefc 'echo hi' /tmp/test.log`) run directly, on the same machine.