fix(remote): resolve remembered explicit-port endpoints

- Resolve bare remote hosts through the remote registry when one explicit port is stored.
- Preserve bare host behavior when no unique explicit-port registry match exists.
- Route requested remote targets through the new registry resolver.
- Add registry tests for unique and ambiguous explicit-port matches.
- Bump package and extension versions to 0.16.6.

extension/manifest.json

@@ -1,7 +1,7 @@
 {
   "manifest_version": 3,
   "name": "browser-cli",
-  "version": "0.16.5",
+  "version": "0.16.6",
   "description": "Control your browser from the terminal or Python SDK",
   "browser_specific_settings": {
     "gecko": {