app: ship a README.md in every support bundle and blackbox capture

An agent handed a bundle path had no way to know its layout without
grepping through random logs first — confirmed by watching a separate
session read bee-nvidia.log before anything else on a real bundle. Embeds
a single README.md (bee-embed, internal/app/assets/) explaining what bee
is and giving direct answers to the questions someone analyzing a bundle
is most likely to ask (did the tests pass, what hardware is this, is a
service healthy, RAID/GPU/NVLink state, etc), written at the bundle root
by both BuildSupportBundle (support-bundle archive root, sibling of
manifest.txt) and blackboxWorker.syncCycle (removable-media boot-folder
root, which otherwise has no manifest.txt-equivalent pointing anywhere).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

audit/internal/app/support_bundle.go

@@ -4,6 +4,7 @@ import (
 	"archive/tar"
 	"bee/audit/internal/platform"
 	"compress/gzip"
+	_ "embed"
 	"fmt"
 	"io"
 	"os"
@@ -14,6 +15,19 @@ import (
 	"time"
 )
 
+//go:embed assets/README.md
+var supportBundleReadmeMD []byte
+
+// writeBundleDocs writes README.md at root, so an AI agent (or a human)
+// analyzing this export (support bundle or blackbox capture) can orient
+// itself without reverse-engineering the directory layout first.
+func writeBundleDocs(root string) error {
+	if err := os.MkdirAll(root, 0755); err != nil {
+		return err
+	}
+	return os.WriteFile(filepath.Join(root, "README.md"), supportBundleReadmeMD, 0644)
+}
+
 var supportBundleServices = []string{
 	"bee-blackbox.service",
 	"bee-audit.service",
@@ -439,6 +453,9 @@ func BuildSupportBundle(exportDir string) (string, error) {
 	for _, item := range supportBundleOptionalFiles {
 		_ = copyOptionalFile(item.src, filepath.Join(stageRoot, item.name))
 	}
+	if err := writeBundleDocs(stageRoot); err != nil {
+		return "", err
+	}
 	if err := writeManifest(filepath.Join(stageRoot, "manifest.txt"), exportDir, stageRoot); err != nil {
 		return "", err
 	}