Show edge and site versions with Update buttons; Update now for Hammerhead itself

Edges and sites report their version and whether auto-update is on. Hammerhead can ask a machine that
has auto-update on to install the newest release, and shows the outcome. Requests carry an ID so a
stale result can't answer a new one.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

e2e/e2e_test.go

@@ -241,6 +241,9 @@ func selfSigned(t *testing.T, host string) *tls.Certificate {
 
 // ---------- the environment ----------
 
+// siteCfgHook lets a test adjust the Bamboo that setup starts.
+var siteCfgHook func(*bamboo.Config)
+
 type world struct {
 	t       *testing.T
 	ts      *httptest.Server
@@ -297,7 +300,11 @@ func setup(t *testing.T, tr blacktip.TraefikConfig, opts ...func(*blacktip.Confi
 		t.Fatal(err)
 	}
 	go bt.Run(ctx)
-	bb, err := bamboo.New(bamboo.Config{Hammerhead: w.ts.URL, Token: site.Token, DataDir: t.TempDir()})
+	bbCfg := bamboo.Config{Hammerhead: w.ts.URL, Token: site.Token, DataDir: t.TempDir()}
+	if siteCfgHook != nil {
+		siteCfgHook(&bbCfg)
+	}
+	bb, err := bamboo.New(bbCfg)
 	if err != nil {
 		t.Fatal(err)
 	}