feat(02-03): create alertService with deduplication and email

- evaluateAndAlert() iterates ProbeResults and skips healthy probes
- Maps 'down' -> 'service_down', 'degraded' -> 'service_degraded'
- Deduplication via AlertEventModel.findRecentByService with configurable cooldown
- Creates alert_events row before sending email (suppression skips both)
- Recipient read from process.env.EMAIL_WEEKLY_RECIPIENT (never hardcoded)
- createTransporter() called inside function scope (Firebase Secret timing fix)
- Email failures caught and logged, never re-thrown

backend/sql/cleanup_old_data.sql

@@ -0,0 +1,102 @@
+-- ============================================================
+-- CLEANUP OLD DATA - Run in Supabase SQL Editor
+-- ============================================================
+-- Removes stale data that accumulates over time without
+-- impacting application functionality.
+--
+-- SAFE TO RUN: All deleted data is either intermediate
+-- processing artifacts or analytics logs. Core document
+-- data (documents, document_chunks, analysis_data) is
+-- never touched by DELETE statements.
+--
+-- Skips tables that don't exist yet (safe for any state).
+--
+-- RECOMMENDATION: Run the check_table_sizes.sql query first
+-- to see how much data will be affected.
+-- ============================================================
+
+DO $$
+DECLARE
+  deleted bigint;
+BEGIN
+
+  -- 1. Processing jobs: completed/failed older than 30 days
+  IF EXISTS (SELECT 1 FROM pg_class c JOIN pg_namespace n ON n.oid = c.relnamespace WHERE n.nspname = 'public' AND c.relname = 'processing_jobs') THEN
+    DELETE FROM processing_jobs WHERE status IN ('completed', 'failed') AND completed_at < NOW() - INTERVAL '30 days';
+    GET DIAGNOSTICS deleted = ROW_COUNT;
+    RAISE NOTICE 'processing_jobs: deleted % rows', deleted;
+  END IF;
+
+  -- 2. Execution events: older than 30 days
+  IF EXISTS (SELECT 1 FROM pg_class c JOIN pg_namespace n ON n.oid = c.relnamespace WHERE n.nspname = 'public' AND c.relname = 'execution_events') THEN
+    DELETE FROM execution_events WHERE created_at < NOW() - INTERVAL '30 days';
+    GET DIAGNOSTICS deleted = ROW_COUNT;
+    RAISE NOTICE 'execution_events: deleted % rows', deleted;
+  END IF;
+
+  -- 3. Session events: older than 30 days
+  IF EXISTS (SELECT 1 FROM pg_class c JOIN pg_namespace n ON n.oid = c.relnamespace WHERE n.nspname = 'public' AND c.relname = 'session_events') THEN
+    DELETE FROM session_events WHERE created_at < NOW() - INTERVAL '30 days';
+    GET DIAGNOSTICS deleted = ROW_COUNT;
+    RAISE NOTICE 'session_events: deleted % rows', deleted;
+  END IF;
+
+  -- 4. Performance metrics: older than 90 days
+  IF EXISTS (SELECT 1 FROM pg_class c JOIN pg_namespace n ON n.oid = c.relnamespace WHERE n.nspname = 'public' AND c.relname = 'performance_metrics') THEN
+    DELETE FROM performance_metrics WHERE created_at < NOW() - INTERVAL '90 days';
+    GET DIAGNOSTICS deleted = ROW_COUNT;
+    RAISE NOTICE 'performance_metrics: deleted % rows', deleted;
+  END IF;
+
+  -- 5. Vector similarity searches: older than 90 days
+  IF EXISTS (SELECT 1 FROM pg_class c JOIN pg_namespace n ON n.oid = c.relnamespace WHERE n.nspname = 'public' AND c.relname = 'vector_similarity_searches') THEN
+    DELETE FROM vector_similarity_searches WHERE created_at < NOW() - INTERVAL '90 days';
+    GET DIAGNOSTICS deleted = ROW_COUNT;
+    RAISE NOTICE 'vector_similarity_searches: deleted % rows', deleted;
+  END IF;
+
+  -- 6. Service health checks: older than 30 days (INFR-01)
+  IF EXISTS (SELECT 1 FROM pg_class c JOIN pg_namespace n ON n.oid = c.relnamespace WHERE n.nspname = 'public' AND c.relname = 'service_health_checks') THEN
+    DELETE FROM service_health_checks WHERE created_at < NOW() - INTERVAL '30 days';
+    GET DIAGNOSTICS deleted = ROW_COUNT;
+    RAISE NOTICE 'service_health_checks: deleted % rows', deleted;
+  END IF;
+
+  -- 7. Alert events: resolved older than 30 days (INFR-01)
+  IF EXISTS (SELECT 1 FROM pg_class c JOIN pg_namespace n ON n.oid = c.relnamespace WHERE n.nspname = 'public' AND c.relname = 'alert_events') THEN
+    DELETE FROM alert_events WHERE status = 'resolved' AND created_at < NOW() - INTERVAL '30 days';
+    GET DIAGNOSTICS deleted = ROW_COUNT;
+    RAISE NOTICE 'alert_events: deleted % rows', deleted;
+  END IF;
+
+  -- 8. Agent executions: older than 90 days
+  IF EXISTS (SELECT 1 FROM pg_class c JOIN pg_namespace n ON n.oid = c.relnamespace WHERE n.nspname = 'public' AND c.relname = 'agent_executions') THEN
+    DELETE FROM agent_executions WHERE created_at < NOW() - INTERVAL '90 days';
+    GET DIAGNOSTICS deleted = ROW_COUNT;
+    RAISE NOTICE 'agent_executions: deleted % rows', deleted;
+  END IF;
+
+  -- 9. Processing quality metrics: older than 90 days
+  IF EXISTS (SELECT 1 FROM pg_class c JOIN pg_namespace n ON n.oid = c.relnamespace WHERE n.nspname = 'public' AND c.relname = 'processing_quality_metrics') THEN
+    DELETE FROM processing_quality_metrics WHERE created_at < NOW() - INTERVAL '90 days';
+    GET DIAGNOSTICS deleted = ROW_COUNT;
+    RAISE NOTICE 'processing_quality_metrics: deleted % rows', deleted;
+  END IF;
+
+  -- 10. Agentic RAG sessions: completed older than 90 days
+  IF EXISTS (SELECT 1 FROM pg_class c JOIN pg_namespace n ON n.oid = c.relnamespace WHERE n.nspname = 'public' AND c.relname = 'agentic_rag_sessions') THEN
+    DELETE FROM agentic_rag_sessions WHERE status IN ('completed', 'failed') AND created_at < NOW() - INTERVAL '90 days';
+    GET DIAGNOSTICS deleted = ROW_COUNT;
+    RAISE NOTICE 'agentic_rag_sessions: deleted % rows', deleted;
+  END IF;
+
+  -- 11. Null out extracted_text for completed documents older than 30 days
+  IF EXISTS (SELECT 1 FROM pg_class c JOIN pg_namespace n ON n.oid = c.relnamespace WHERE n.nspname = 'public' AND c.relname = 'documents') THEN
+    UPDATE documents SET extracted_text = NULL
+    WHERE status = 'completed' AND analysis_data IS NOT NULL AND extracted_text IS NOT NULL AND created_at < NOW() - INTERVAL '30 days';
+    GET DIAGNOSTICS deleted = ROW_COUNT;
+    RAISE NOTICE 'documents extracted_text nulled: % rows', deleted;
+  END IF;
+
+  RAISE NOTICE '--- CLEANUP COMPLETE ---';
+END $$;