refactor: rename daemon binary from owlry-core to owlryd

- Binary: owlry-core → owlryd
- Systemd: owlry-core.service → owlryd.service, owlry-core.socket → owlryd.socket
- Client: systemctl start owlryd
- AUR package name stays owlry-core (installs owlryd binary)

systemd/owlryd.socket

@@ -0,0 +1,9 @@
+[Unit]
+Description=Owlry launcher socket
+
+[Socket]
+ListenStream=%t/owlry/owlry.sock
+DirectoryMode=0700
+
+[Install]
+WantedBy=sockets.target