chore(native-host): group modules into proxy/, managers/, host/

- Move connect-proxy and https-proxy into proxy/
- Move certificate-authority, backup-manager, ssh-manager, rdp-manager into managers/
- Move messenger.js into host/
- Move test-dirname.cjs into test/
- Update imports, CI lint paths, and ARCHITECTURE.md

native-host/test/test-dirname.cjs

@@ -0,0 +1,11 @@
+const path = require('bare-path');
+console.log('__dirname:', __dirname);
+const DEV_DASHBOARD_DIR = path.join(__dirname, '..', 'extension', 'dashboard');
+console.log('DEV_DASHBOARD_DIR:', DEV_DASHBOARD_DIR);
+const fs = require('bare-fs');
+try {
+  const f = fs.readFileSync(path.join(DEV_DASHBOARD_DIR, 'dashboard.html'));
+  console.log('READ OK, size:', f.length);
+} catch(e) {
+  console.log('READ FAILED:', e.message);
+}