feat: add deployment foundation and cross-device handoff

internal/preflight/collect_linux.go

@@ -0,0 +1,22 @@
+//go:build linux
+
+package preflight
+
+import (
+	"os"
+	"syscall"
+
+	"server-deploy/internal/inspect"
+)
+
+func Collect() Report {
+	return Probe(inspect.Collect(), os.DirFS("/"), os.Geteuid(), diskAvailable("/var/lib"))
+}
+
+func diskAvailable(path string) Disk {
+	var stat syscall.Statfs_t
+	if syscall.Statfs(path, &stat) != nil || stat.Bsize <= 0 || stat.Bavail > ^uint64(0)/uint64(stat.Bsize) {
+		return Disk{State: "unknown"}
+	}
+	return Disk{State: "observed", AvailableBytes: stat.Bavail * uint64(stat.Bsize)}
+}