Add end-to-end tests for TLS RPT report ingestion and WebSocket event handling

- Implemented tests for ingesting TLS RPT reports from emails and ensuring they are stored correctly in the database.
- Added tests to verify that the same report can be ingested multiple times without duplication.
- Created tests for backfilling reports that were previously delivered to the inbox.
- Developed WebSocket event handling tests to ensure events are correctly routed to subscribers based on mailbox ownership.
- Included tests for the mail API to validate session handling, mailbox isolation, and error mapping.
- Ensured that the API rejects unauthorized requests and handles malformed JSON gracefully.

services/protocols/cmd/lambdamail-protocols/backfill_reports.go

@@ -0,0 +1,50 @@
+package main
+
+import (
+	"context"
+	"log"
+	"time"
+
+	"lambdamail/protocols/internal/application/usecase"
+	"lambdamail/protocols/internal/infrastructure/diskstorage"
+	"lambdamail/protocols/internal/infrastructure/postgres"
+)
+
+// runBackfillReports parses the DMARC and TLS-RPT reports that were delivered
+// before automatic ingestion existed.
+//
+// Run by hand, once, after deploying ingestion: every report received until
+// then was filed in the admin's inbox as an attachment nothing ever read, so
+// the tables the console shows start empty however long the server has been
+// running. Safe to run more than once - storing a report is idempotent, and a
+// message already filed in Reports is not picked up again.
+func runBackfillReports(cfg config) {
+	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Minute)
+	defer cancel()
+
+	pool, err := postgres.NewPool(ctx, cfg.DatabaseURL)
+	if err != nil {
+		log.Fatalf("backfill: cannot reach the database: %v", err)
+	}
+	defer pool.Close()
+
+	// The reader alone: the backfill only ever reads stored messages back out.
+	blobs := diskstorage.NewLocalDiskBlobReader(pool)
+
+	store := postgres.NewDeliveredReportStore(pool)
+	uc := usecase.NewBackfillReportsUseCase(store, blobs,
+		usecase.NewIngestDeliveredReportsUseCase(
+			usecase.NewIngestReportsUseCase(postgres.NewReportRepository(pool))))
+
+	summary, err := uc.Run(ctx, 0)
+	if err != nil {
+		log.Fatalf("backfill: %v", err)
+	}
+
+	log.Printf("backfill: scanned %d stored reports, ingested %d, could not read %d",
+		summary.Scanned, summary.Ingested, summary.Failed)
+	if summary.Failed > 0 {
+		log.Printf("backfill: the unreadable ones are filed in Reports with their " +
+			"bytes intact, so this can be run again once the cause is fixed")
+	}
+}