Apply PR #144 review round 2: settings-based service kwargs, required settings, shim removal, hardened AST scan

P2: services._generation_kwargs now reads runtime.settings.horizon_days
instead of re-implementing the bool/non-int/<1 fallback against
runtime.options; drop the now-unused CONF_HORIZON_DAYS/DEFAULT_HORIZON_DAYS
imports. Remove NestQuestRuntimeData.options (kept only for that read; the
admin-id path reads entry.options directly) and the matching test assertion.

P3: _run_horizon_materialization's settings param is now REQUIRED (drop the
'| None = None' default + the NestQuestSettings() substitution branch);
update the test_timezones callers to pass NestQuestSettings() explicitly.

P3: __post_init__ normalises notify_target via _resolve_optional_str (strip)
so a hand-built NestQuestSettings(notify_target=' x ') behaves like the
options flow; keep the docstring accurate.

P3: delete the custom_components/nestquest/settings.py shim (settings is a
new module with no legacy import path) and import NestQuestSettings from
.core.settings directly in __init__.py, in alphabetical position.

P3: harden the AST scan for importlib.import_module('homeassistant...')
(string-based import) and call keyword names like hass= (ast.keyword);
add negative-control cases for each; explain in the failure message why
.config/.options/.data are banned (HA config-entry attributes with no
legitimate core use).

P3: drive from_options and from_options_resilient from one _FIELDS table of
(field, key, default, validator) to avoid three-way drift.

uv run pytest -q: 1573 passed.

custom_components/nestquest/services.py

@@ -24,8 +24,6 @@ from . import children as children_layer
 from . import completion as completion_layer
 from . import quest_definitions as quest_definitions_layer
 from .const import (
-    CONF_HORIZON_DAYS,
-    DEFAULT_HORIZON_DAYS,
     DOMAIN,
     DOMAIN_SERVICES,
     QUEST_WINDOWS,
@@ -258,12 +256,7 @@ async def _refresh_entities(runtime: Any) -> None:
 def _generation_kwargs(hass: HomeAssistant, runtime: Any) -> dict[str, Any]:
     time_zone = ZoneInfo(hass.config.time_zone)
     today = datetime.datetime.now(time_zone).date()
-    value = runtime.options.get(CONF_HORIZON_DAYS, DEFAULT_HORIZON_DAYS)
-    if isinstance(value, bool) or not isinstance(value, int) or value < 1:
-        horizon_days = DEFAULT_HORIZON_DAYS
-    else:
-        horizon_days = value
-    return {"today": today, "horizon_days": horizon_days}
+    return {"today": today, "horizon_days": runtime.settings.horizon_days}
 
 
 def _actor_kwargs(call: Any) -> dict[str, Any]: