Remove the HA admin services and the service permission gate

Since Feature 18 the integration is a client of the NestQuest API
service and the admin surface is the PWA plus the API's admin routes,
so the integration must not keep HA services for admin operations.
Drop every admin service handler and its registration (uncomplete,
create/update/set-active quest definition, presence pattern and
overrides, CSV export, manage_child, regenerate) together with the
Feature 09 permission gate that existed only for them: permissions.py,
service_policy.py and the core SERVICE_POLICY registry, the
regenerate handler plumbing in __init__, the dead payload schemas and
services.yaml entries, and the service-name constants they alone
used. Only the panel completion path (nestquest.complete_quest)
remains, still proxying to the entry's shared API client. The four
automation blueprints are untouched — they only read sensors and
listen to bus events.

custom_components/nestquest/events.py

@@ -4,8 +4,10 @@ The transition-event payload construction lives in
 :mod:`custom_components.nestquest.core.events` (extracted in
 task 510c1f78) and is HA-free: it builds and RETURNS the events.  This
 shim keeps the integration's old ``fire_quest_completed`` /
-``fire_quest_uncompleted`` API (the complete/uncomplete service
-handlers call them with ``hass``), reads the HA-local timezone from
+``fire_quest_uncompleted`` API for direct callers — since Feature 18
+the HA service surface no longer fires transition events itself (the
+API service publishes them on its SSE stream and the integration's
+subscription re-fires them) — reads the HA-local timezone from
 ``hass.config.time_zone`` to derive ``today``, asks the core builder
 for the events, and fires each on ``hass.bus`` with the documented
 payloads.  The four blueprints keep working with identical payloads.