feat(auth): add interactive key policy editing

- Add auth policy to update existing authorized_keys allow policies locally or over remote serve.
- Support key lookup by public key or exact name, with safe, all, server-default, and category-based modes.
- Add questionary-powered interactive key selection and checkbox policy editing with current policy preselected.
- Show policy descriptions in auth keys output so each capability is easier to understand.
- Gate the new remote control command behind the existing keys policy category and include protocol routing/compat updates.
- Bump real-browser-cli to 0.16.2 and lock the new questionary dependency.
- Cover local, remote, validation, and policy-category behavior in tests.

browser_cli/auth/__init__.py

@@ -24,6 +24,7 @@ from browser_cli.auth.keys import (
   load_authorized_keys_with_policies,
   load_private_key,
   public_key_hex,
+  set_authorized_key_policy,
 )
 from browser_cli.auth.pq import (
   new_nonce,
@@ -66,6 +67,7 @@ __all__ = [
   "pq_kex_server_decapsulate",
   "pq_kex_server_keypair",
   "public_key_hex",
+  "set_authorized_key_policy",
   "sign",
   "verify",
 ]