fix(e2e): read setup-token via exec; reclaim /data

Container startup is green; CI failed because panel-owned setup-token (0600)
was unreadable on the host bind mount, and TempDir cleanup hit EACCES on
sqlite/opendkim files. Read the token with compose exec (as guide.md) and
chown /data before removing containers/stage.

Co-Authored-By: Composer <noreply@cursor.com>
Co-authored-by: Cursor <cursoragent@cursor.com>

test/e2e/main_test.go

@@ -54,6 +54,10 @@ func TestMain(m *testing.M) {
 			fmt.Fprintf(os.Stderr, "\n==== logs: %s ====\n%s\n", svc, s.logs(svc))
 		}
 	}
+	// Panel/postfix-owned files under the /data bind mount outlive the
+	// container; reclaim ownership while selfpost is still up so a later
+	// prepareStage RemoveAll (or a local re-run) is not stuck on EACCES.
+	s.reclaimData()
 	s.down()
 	os.Exit(code)
 }
@@ -107,7 +111,7 @@ func TestE2E(t *testing.T) {
 	})
 
 	run("setup_and_login", func(t *testing.T) {
-		token, err := readSetupToken(h.stageDir)
+		token, err := readSetupToken(h)
 		if err != nil {
 			t.Fatalf("read setup token: %v", err)
 		}