**Title:** `omarchy-install-hermes-cli` readiness probe never passes — `--oneshot` lives at the top level of `hermes --help`, not under `hermes chat --help`

### Summary

`omarchy-install-hermes-cli --check` always exits 1 against the current Hermes Agent release, so Omarchy never recognizes Hermes as ready and reports "Hermes installed without the interactive seeded sessions Omarchy needs." Hermes does support interactive seeded sessions — the failure is in the probe.

### What I expected

With Hermes Agent installed and runnable, `omarchy-install-hermes-cli --check` (and the `--now` install path) should exit 0, letting the menu / floating terminal / `hermes` default agent launch properly.

### What happened

`hermes_prompt_ready()` probes only `hermes chat --help` for the string `--oneshot`:

```bash
# bin/omarchy-install-hermes-cli
hermes_prompt_ready() {
  local help
  hermes_runs &&
    help=$(timeout 15 "$HOME/.local/bin/hermes" chat --help 2>/dev/null) &&
    grep -qF -- '--oneshot' <<<"$help"
}
```

But Hermes Agent wires `--oneshot` (aliased `-z`) at the **top-level `hermes` command**, not under `hermes chat`. So the string never appears in `chat --help`, and the check always fails.

### Steps to reproduce

```bash
hermes --version
# Hermes Agent v0.19.0 (2026.7.20)  — latest release as of 2026-09-02

hermes chat --help | grep --oneshot   # -> no output
hermes --help     | grep --oneshot   # ->  -z, --oneshot PROMPT  One-shot mode: ...

omarchy-install-hermes-cli --check
echo $?   # -> 1
```

### System details

- Omarchy: `4.0.0.r2004.gb71dcad-1` (`VERSION_ID=4.0.0.r2004.gb71dcad`, Arch-based)
- Hermes Agent: `v0.19.0` (2026.7.20), installed via the Omarchy mise-backed wrapper in `~/.local/bin/hermes`
- Hardware: Dell Precision 5540, Intel i7-9750H, Intel UHD 630 + NVIDIA Quadro T1000 Mobile
- Presumably affects every current Hermes release, since the flag has been top-level in `hermes --help` in the installed and source versions inspected. The commit "Use Hermes native prompted sessions" (2026-08-28) appears to be what introduced the `chat --help`-only probe.

### Suggested fix

Check **either** help surface so the probe stays version-robust (top-level `-z/--oneshot` today, and a `chat`-level spelling in newer builds):

```bash
hermes_prompt_ready() {
  local help chat_help
  hermes_runs &&
    help=$(timeout 15 "$HOME/.local/bin/hermes" --help 2>/dev/null) &&
    chat_help=$(timeout 15 "$HOME/.local/bin/hermes" chat --help 2>/dev/null) &&
    grep -qF -- '--oneshot' <<<"$help$chat_help"
}
```

I've applied this locally (with a backup) so my machine works; this issue is so the fix lands upstream, since any local patch is overwritten by `omarchy update`.

The file also ships a test at `test/shell.d/hermes-cli-test.sh` that may need a companion case for the top-level flag.

**Workaround for other users:** patch the probe in the installer (installed as `/usr/bin/omarchy-install-hermes-cli`, symlinked from `/usr/share/omarchy/bin`) to check `hermes --help` too — but it's overwritten on update, hence this report.