feat: rename service to galo, add halo branding and release build

- rename Go module, binary, systemd unit, PG_DATABASE default, frontend package and docs from shared-album to galo
- add theme-aware halo emblem and favicon (new ui-branding capability)
- add make build-release (versioned, stripped, static binary) and run the binary from the repo root

deploy/galo.service

@@ -0,0 +1,24 @@
+[Unit]
+Description=Galo backend
+After=network-online.target
+Wants=network-online.target
+
+[Service]
+Type=simple
+User=album
+Group=album
+WorkingDirectory=/opt/galo
+EnvironmentFile=/opt/galo/.env
+ExecStart=/opt/galo/galo
+Restart=on-failure
+RestartSec=5s
+
+# Безопасность
+NoNewPrivileges=true
+PrivateTmp=true
+ProtectSystem=strict
+ProtectHome=true
+ReadWritePaths=/opt/galo
+
+[Install]
+WantedBy=multi-user.target