### What happened

`omarchy install service sunshine` aborts partway through. Sunshine gets installed, but the
firewall rules, the admin web app, and the autostart entry are never applied, so Moonlight
cannot reach the host and the service does not start with the session.

```
Installing Sunshine...
...
installing sunshine...
Failed to enable unit: Unit sunshine.service does not exist
```

### Root cause

`bin/omarchy-install-service-sunshine` line 74 enables the unit by a name that does not exist yet:

```bash
systemctl --user enable --now sunshine
```

The `sunshine` package ships its unit as **`app-dev.lizardbyte.app.Sunshine.service`**:

```
$ pacman -Ql sunshine | grep systemd
sunshine /usr/lib/systemd/user/app-dev.lizardbyte.app.Sunshine.service
```

That unit does declare `Alias=sunshine.service`, but a systemd `Alias=` symlink is only created
*when the unit is enabled*. On a clean install the alias therefore does not resolve yet, and
`systemctl --user enable --now sunshine` fails. Because the script runs under `set -e`, it exits
right there — before `open_ufw_ports`, `install_admin_webapp` and `enable_hyprland_autostart`.

The result is a half-installed service that looks installed: the package is present, but the
firewall is closed, there is no admin web app, and Sunshine never starts on login.

### Steps to reproduce

On a machine that has never had Sunshine installed:

```bash
omarchy install service sunshine
```

Observe `Failed to enable unit: Unit sunshine.service does not exist` and a non-zero exit, and
confirm the follow-up steps were skipped:

```bash
ufw status | grep omarchy-sunshine        # no rules
ls ~/.local/share/applications | grep -i sunshine   # no admin webapp
```

Note that re-running the command after manually enabling the unit once will *appear* to work,
because the alias symlink now exists — so this only reproduces from a clean state.

### Expected

The installer enables the unit the package actually ships and completes all of its steps.

### Suggested fix

Enable the real unit name:

```bash
systemctl --user enable --now app-dev.lizardbyte.app.Sunshine.service
```

### Secondary observation

`enable_hyprland_autostart` appends `o.launch_on_start("sunshine")` to `hypr/autostart.lua`, but
the shipped unit is already `WantedBy=graphical-session.target`. Once the unit is enabled
correctly, that line starts a second instance. It may be worth dropping the autostart entry and
relying on the unit, though I have only reasoned about this rather than tested the double-start.

### System

- Omarchy 4.0.1-1 (channel: stable)
- sunshine 2026.516.143833-4 (omarchy repo)
- systemd 261.2-1-arch
- Hyprland 0.56.2

Verified still present on `quattro` @ HEAD: the file at
`bin/omarchy-install-service-sunshine` is byte-identical to my installed copy.

I skipped the `omarchy debug` dump because this is a logic bug in the script, reproducible
independently of hardware — happy to attach it if useful.