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/jchv/go-winloader/internal/pe/util.go

@@ -0,0 +1,40 @@
+package pe
+
+import "io"
+
+func readfully(r io.Reader, p []byte) error {
+	n, err := r.Read(p)
+	if n < 0 || n > len(p) {
+		panic("invalid read length")
+	}
+	if err != nil && err != io.EOF {
+		return err
+	}
+	for n < len(p) {
+		m, err := r.Read(p[n:])
+		if m < 0 || m > len(p[n:]) {
+			panic("invalid read length")
+		}
+		n += m
+		if n < len(p) && err != nil {
+			return err
+		}
+		if n >= len(p) && err != nil && err != io.EOF {
+			return err
+		}
+	}
+	return nil
+}
+
+func readsz(r io.Reader) string {
+	name := []byte{}
+	for {
+		b := [1]byte{}
+		r.Read(b[:])
+		if b[0] == 0 {
+			break
+		}
+		name = append(name, b[0])
+	}
+	return string(name)
+}