Replaces #7676
When building as a flatpak, don't install the systemd user services
since flatpaks can't use them. Remove references to the systemd service
from the DBus service.
Also, customize the app metadata depending on the debug mode.
Co-authored-by: Leorize <leorize+oss@disroot.org>
Reverts two commits:
977cd530c7bb9551de93900170bdaec4601b1b5b
820b7e432b57cd08c49d2e76cce4cb78016f0418
These break build from source on Linux for two reasons:
1.) The systemd user service needs to be installed in the `share`
prefix, not the `lib` prefix. This lets it get picked up in `~/.local`
but is also correct for just standard FHS paths.
2.) The `ghostty` path in the systemd user service needs to be absolute.
We should interpolate in the build install prefix to form an absolute
path.
Flatpak currently does not export systemd user units. As such, remove
references to it from D-Bus services to prevent D-Bus daemon from trying
to start a non-existent service.
Additionally, make sure that the D-Bus service name is correct for debug
builds.
This is done to match against the default application id when Ghostty is
built using debug configuration, done to prepare the Flatpak version for
D-Bus activation support.
