refactor(automations): vertical-slice actions and triggers by domain

surfsense_backend/app/automations/triggers/store.py

@@ -0,0 +1,23 @@
+"""In-memory trigger registry. Populated once at process startup."""
+
+from __future__ import annotations
+
+from .types import TriggerDefinition
+
+_REGISTRY: dict[str, TriggerDefinition] = {}
+
+
+def register_trigger(trigger: TriggerDefinition) -> None:
+    """Register a trigger. Raises on duplicate type."""
+    if trigger.type in _REGISTRY:
+        raise ValueError(f"Trigger already registered: {trigger.type!r}")
+    _REGISTRY[trigger.type] = trigger
+
+
+def get_trigger(trigger_type: str) -> TriggerDefinition | None:
+    return _REGISTRY.get(trigger_type)
+
+
+def all_triggers() -> dict[str, TriggerDefinition]:
+    """Defensive snapshot of the registry."""
+    return dict(_REGISTRY)