Switch remote deploy to vendored source builds

Move remote deployment to a vendored source bundle built on the target host via Docker so redeploys no longer require local cross-compilation or host Go installation.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

vendor/github.com/godbus/dbus/v5/conn_unix.go

@@ -0,0 +1,17 @@
+//+build !windows,!solaris,!darwin
+
+package dbus
+
+import (
+	"os"
+)
+
+const defaultSystemBusAddress = "unix:path=/var/run/dbus/system_bus_socket"
+
+func getSystemBusPlatformAddress() string {
+	address := os.Getenv("DBUS_SYSTEM_BUS_ADDRESS")
+	if address != "" {
+		return address
+	}
+	return defaultSystemBusAddress
+}