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.

tests/test_serve_security.py

@@ -42,10 +42,11 @@ def test_key_commands_are_keys_category():
   from browser_cli.command_security import command_category
   assert command_category("browser-cli.auth.keys") == "keys"
   assert command_category("browser-cli.auth.trust") == "keys"
+  assert command_category("browser-cli.auth.policy") == "keys"
   assert command_category("browser-cli.targets") == "safe"  # discovery stays open
 
 def test_key_commands_blocked_without_allow_keys():
-  for cmd in ("browser-cli.auth.keys", "browser-cli.auth.trust"):
+  for cmd in ("browser-cli.auth.keys", "browser-cli.auth.trust", "browser-cli.auth.policy"):
     with pytest.raises(PermissionError):
       assert_command_allowed(cmd, CommandPolicy())               # safe-only default
     assert_command_allowed(cmd, CommandPolicy(allow_keys=True))  # explicit grant