chore: synchronize pending app/backend updates and repository hygiene

Includes current frontend and backend work in progress and removes generated artifacts from tracking to keep the repository clean for дальнейшая разработка.

Co-authored-by: Cursor <[email protected]>

backend/src/services/alert-engine/snapshot.ts

@@ -0,0 +1,7 @@
+import { buildSignalSnapshotFromCollectors } from "./signals-from-collectors.js"
+import type { SignalSnapshot } from "./types.js"
+
+/** Legacy-совместимость: единый источник сигналов — collector snapshots из scheduler_runs. */
+export function buildSignalSnapshot(): SignalSnapshot {
+  return buildSignalSnapshotFromCollectors()
+}