Add browser deploy recon backend with port scan, web crawl, and deploy lane recommendations.

POST /api/v1/recon/scan probes fleet ports from the server host, crawls owned HTTP targets, maps findings to spread lanes, and records optional oath ledger rows.

server/internal/recon/html_tree.go

@@ -0,0 +1,40 @@
+package recon
+
+import (
+	"strings"
+
+	"golang.org/x/net/html"
+)
+
+type htmlNode struct {
+	tag      string
+	attrs    map[string]string
+	children []*htmlNode
+}
+
+func (n *htmlNode) attr(key string) string {
+	if n == nil || n.attrs == nil {
+		return ""
+	}
+	return n.attrs[key]
+}
+
+func parseHTMLTree(body string) (*html.Node, error) {
+	return html.Parse(strings.NewReader(body))
+}
+
+func toHTMLNode(n *html.Node) *htmlNode {
+	if n == nil {
+		return nil
+	}
+	out := &htmlNode{tag: n.Data, attrs: map[string]string{}}
+	for _, a := range n.Attr {
+		out.attrs[a.Key] = a.Val
+	}
+	for c := n.FirstChild; c != nil; c = c.NextSibling {
+		if child := toHTMLNode(c); child != nil {
+			out.children = append(out.children, child)
+		}
+	}
+	return out
+}