feat(notify): add toggle_per_crack_enabled runtime toggle

Promotes notify_per_crack_enabled from config-file-only to a runtime
toggle with the same style (global-decl, default-init, OSError-via-logger)
as the existing toggle_enabled, with full TDD coverage.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

hate_crack/notify/__init__.py

@@ -49,6 +49,7 @@ from hate_crack.notify.settings import (
     add_to_allowlist,
     load_settings,
     save_enabled,
+    save_per_crack_enabled,
 )
 from hate_crack.notify.tailer import (
     CrackTailer,
@@ -91,6 +92,7 @@ __all__ = [
     "stop_tailer",
     "suppressed_notifications",
     "toggle_enabled",
+    "toggle_per_crack_enabled",
     "_send_pushover",
 ]
 
@@ -145,6 +147,24 @@ def toggle_enabled() -> bool:
     return _settings.enabled
 
 
+def toggle_per_crack_enabled() -> bool:
+    """Flip ``notify_per_crack_enabled``, persist to ``config.json``, return new state.
+
+    If ``init`` was never called we still toggle an in-memory default — the
+    UI update must not crash even if the config file is unreachable.
+    """
+    global _settings
+    if _settings is None:
+        _settings = NotifySettings()
+    _settings.per_crack_enabled = not _settings.per_crack_enabled
+    if _config_path:
+        try:
+            save_per_crack_enabled(_config_path, _settings.per_crack_enabled)
+        except OSError as exc:
+            logger.warning("Could not persist notify_per_crack_enabled: %s", exc)
+    return _settings.per_crack_enabled
+
+
 def _in_allowlist(attack_name: str) -> bool:
     return attack_name in get_settings().attack_allowlist
 

tests/test_notify_per_crack_toggle.py

@@ -0,0 +1,67 @@
+"""Unit tests for the toggle_per_crack_enabled runtime toggle."""
+import json
+from pathlib import Path
+
+from hate_crack import notify as _notify
+
+
+def _init_with(tmp_path: Path, **overrides) -> Path:
+    """Seed a config file with defaults + overrides and init the notify module."""
+    config_path = tmp_path / "config.json"
+    cfg = {
+        "notify_enabled": False,
+        "notify_per_crack_enabled": False,
+        "notify_pushover_token": "",
+        "notify_pushover_user": "",
+    }
+    cfg.update(overrides)
+    config_path.write_text(json.dumps(cfg))
+    _notify.init(str(config_path), cfg)
+    return config_path
+
+
+class TestTogglePerCrackEnabled:
+    def test_off_to_on_flips_and_persists(self, tmp_path: Path) -> None:
+        config_path = _init_with(tmp_path)
+        try:
+            new_state = _notify.toggle_per_crack_enabled()
+            assert new_state is True
+            assert _notify.get_settings().per_crack_enabled is True
+            data = json.loads(config_path.read_text())
+            assert data["notify_per_crack_enabled"] is True
+        finally:
+            _notify.clear_state_for_tests()
+
+    def test_on_to_off_flips_and_persists(self, tmp_path: Path) -> None:
+        config_path = _init_with(tmp_path, notify_per_crack_enabled=True)
+        try:
+            new_state = _notify.toggle_per_crack_enabled()
+            assert new_state is False
+            assert _notify.get_settings().per_crack_enabled is False
+            data = json.loads(config_path.read_text())
+            assert data["notify_per_crack_enabled"] is False
+        finally:
+            _notify.clear_state_for_tests()
+
+    def test_toggle_without_init_uses_defaults(self) -> None:
+        # Mirrors the behavior of toggle_enabled: must not crash when init
+        # was never called. The toggle flips an in-memory default; nothing
+        # is persisted because _config_path is None.
+        try:
+            _notify.clear_state_for_tests()
+            new_state = _notify.toggle_per_crack_enabled()
+            assert new_state is True
+            assert _notify.get_settings().per_crack_enabled is True
+        finally:
+            _notify.clear_state_for_tests()
+
+    def test_does_not_touch_global_enabled(self, tmp_path: Path) -> None:
+        config_path = _init_with(tmp_path, notify_enabled=False)
+        try:
+            _notify.toggle_per_crack_enabled()
+            data = json.loads(config_path.read_text())
+            # notify_enabled stays False; only per-crack flipped.
+            assert data["notify_enabled"] is False
+            assert data["notify_per_crack_enabled"] is True
+        finally:
+            _notify.clear_state_for_tests()