test(plugins): picker regression tests drive the real cmd_toggle

Two invariant tests through the real text-fallback picker and real admission
(plugin_world), replacing the helper-level tests from #121623 by
@victor-kyriazakos: open-and-exit writes nothing, and a session that ticks a
legacy-name-disabled platform and unticks another writes exactly those two rows
and keeps an enabled entry for a plugin the picker does not show. Both fail on
main by behaviour; the second also fails on the ported fix alone (the
manifest-name disable survived the tick).

tests/hermes_cli/test_plugins_picker_effective_state.py

@@ -0,0 +1,55 @@
+"""The bare ``hermes plugins`` picker writes only the rows the user flipped.
+
+Bundled platforms are active without a ``plugins.enabled`` entry; the picker used to open them unticked
+and save every unticked row into ``plugins.disabled`` on any exit, so opening and closing it silenced
+Telegram and Slack on the next gateway restart. Drives the real ``cmd_toggle`` (text fallback) through
+real admission.
+"""
+import pytest
+import hermes_yaml as yaml
+
+from tests.hermes_cli.plugin_worker_support import (
+    plugin_world as plugin_world,
+    isolated_python as isolated_python,
+)
+
+
+@pytest.fixture
+def run_picker(plugin_world, monkeypatch):
+    from hermes_cli import plugins_cmd
+
+    world = plugin_world
+    for leaf in ("telegram", "slack"):
+        platform = world.core / "plugins" / "platforms" / leaf
+        platform.mkdir(parents=True)
+        (platform / "plugin.yaml").write_text(f"name: {leaf}-platform\nkind: platform\n", encoding="utf-8")
+    monkeypatch.setattr("hermes_cli.plugins.get_bundled_plugins_dir", lambda: world.core / "plugins")
+    monkeypatch.setattr(plugins_cmd, "_provider_categories", lambda: [])
+    monkeypatch.setattr(plugins_cmd.sys.stdin, "isatty", lambda: True)
+    monkeypatch.setitem(plugins_cmd.sys.modules, "curses", None)
+    config_path = world.home / "config.yaml"
+
+    def _run(plugins: dict, toggle_keys=()):
+        config_path.write_text(yaml.safe_dump({"plugins": plugins}), encoding="utf-8")
+        keys = [entry[5] for entry in plugins_cmd._discover_all_plugins()]
+        answers = iter([str(keys.index(k) + 1) for k in toggle_keys] + [""])
+        monkeypatch.setattr("builtins.input", lambda _prompt: next(answers))
+        plugins_cmd.cmd_toggle()
+        return yaml.safe_load(config_path.read_text(encoding="utf-8"))["plugins"]
+
+    return _run
+
+
+def test_open_and_exit_without_changes_writes_nothing(run_picker):
+    assert run_picker({"enabled": [], "disabled": []}) == {"enabled": [], "disabled": []}
+
+
+def test_only_flipped_rows_are_written(run_picker):
+    # Telegram is disabled under its canonical key AND its legacy manifest name; ticking it must clear
+    # both. Slack is unticked. The enabled entry for a plugin the picker never shows must survive.
+    plugins = run_picker(
+        {"enabled": ["some/unshown-plugin"], "disabled": ["platforms/telegram", "telegram-platform"]},
+        toggle_keys=("platforms/telegram", "platforms/slack"),
+    )
+    assert plugins["disabled"] == ["platforms/slack"]
+    assert sorted(plugins["enabled"]) == ["platforms/telegram", "some/unshown-plugin"]