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_new_feature_commands.py

@@ -237,9 +237,77 @@ def test_auth_keys_local_shows_policy_column(tmp_path):
   result = CliRunner().invoke(main, ["auth", "keys", "--file", str(keys)])
   assert result.exit_code == 0
   assert "Policy" in result.output
+  assert "Description" in result.output
   assert "read-page" in result.output
   assert "all" in result.output
   assert "server default" in result.output
+  assert "read page content" in result.output
+  assert "Full access" in result.output
+
+def test_auth_policy_updates_existing_key_policy(tmp_path):
+  keys = tmp_path / "authorized_keys"
+  pub = "a" * 64
+  keys.write_text(f"{pub} YubiKey 5C NFC FIPS\n")
+  result = CliRunner().invoke(main, [
+    "auth", "policy", pub, "--file", str(keys), "--allow-read-page", "--allow-control",
+  ])
+  assert result.exit_code == 0
+  assert keys.read_text().strip() == f"{pub} YubiKey 5C NFC FIPS allow:read-page,control"
+  assert "Updated policy" in result.output
+
+def test_auth_policy_can_set_safe_and_server_default_by_name(tmp_path):
+  keys = tmp_path / "authorized_keys"
+  pub = "b" * 64
+  keys.write_text(f"{pub} laptop allow:all\n")
+
+  safe_result = CliRunner().invoke(main, ["auth", "policy", "laptop", "--file", str(keys), "--safe"])
+  assert safe_result.exit_code == 0
+  assert keys.read_text().strip() == f"{pub} laptop allow:"
+
+  default_result = CliRunner().invoke(main, ["auth", "policy", "laptop", "--file", str(keys), "--server-default"])
+  assert default_result.exit_code == 0
+  assert keys.read_text().strip() == f"{pub} laptop"
+
+def test_auth_policy_requires_policy_mode_when_not_interactive(tmp_path):
+  keys = tmp_path / "authorized_keys"
+  keys.write_text(f"{'a' * 64} laptop\n")
+  result = CliRunner().invoke(main, ["auth", "policy", "laptop", "--file", str(keys)])
+  assert result.exit_code == 1
+  assert "Choose a policy mode" in result.output
+
+def test_auth_policy_rejects_conflicting_policy_modes(tmp_path):
+  keys = tmp_path / "authorized_keys"
+  keys.write_text(f"{'a' * 64} laptop\n")
+  result = CliRunner().invoke(main, ["auth", "policy", "laptop", "--file", str(keys), "--safe", "--allow-all"])
+  assert result.exit_code == 1
+  assert "Choose exactly one policy mode" in result.output
+
+def test_parse_interactive_policy_selection():
+  from browser_cli.commands.auth import _parse_checkbox_policy_selection, _parse_policy_selection
+
+  assert _parse_policy_selection("1,2") == ["read-page", "control"]
+  assert _parse_policy_selection("read-page control") == ["read-page", "control"]
+  assert _parse_policy_selection("all") == ["all"]
+  assert _parse_policy_selection("safe") == []
+  assert _parse_policy_selection("default") is None
+  assert _parse_checkbox_policy_selection(["read-page", "control"]) == ["read-page", "control"]
+  assert _parse_checkbox_policy_selection(["__all__"]) == ["all"]
+  assert _parse_checkbox_policy_selection(["__safe__"]) == []
+  assert _parse_checkbox_policy_selection(["__server_default__"]) is None
+
+def test_auth_policy_without_identifier_requires_interactive_picker():
+  result = CliRunner().invoke(main, ["auth", "policy", "--allow-all"])
+  assert result.exit_code == 1
+  assert "Missing key identifier" in result.output
+
+def test_auth_policy_remote_sends_policy_command():
+  pub = "c" * 64
+  with patch("browser_cli.client.send_command", return_value={"pubkey": pub, "name": "remote key", "allow": ["all"]}) as send:
+    result = CliRunner().invoke(main, ["--remote", "browser-host.example:8765", "auth", "policy", pub, "--allow-all"])
+  assert result.exit_code == 0
+  send.assert_called_once()
+  assert send.call_args.kwargs["args"] == {"identifier": pub, "allow": ["all"]}
+  assert "Updated policy" in result.output
 
 def test_auth_keys_remote_unreachable_clean_error():
   """`auth keys --remote` on an unreachable host shows a clean error, not a traceback."""