fix: Rollback auf draft bei Versand-Fehlern, Fehlermeldung updateCampaign

- send/route.ts: try/catch + Rollback auf draft wenn Empfänger-Query oder Queue-Enqueue fehlschlägt
- campaigns.ts: Fehlermeldung 'Kampagne nicht im Draft-Status' (zuvor enthielt sie 'nicht gefunden' — verursachte falschen 404 in PATCH)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/app/api/campaigns/[id]/send/route.ts

@@ -17,23 +17,29 @@ export async function POST(req: NextRequest, { params }: { params: { id: string
     return NextResponse.json({ error: 'Nur Draft-Kampagnen können versendet werden' }, { status: 400 })
   }
 
-  // Status auf 'sending' setzen — Ergebnis prüfen (Fix C1)
   const statusResult = await updateCampaignStatus(tenantId, params.id, 'sending')
   if (!statusResult.ok) {
     return NextResponse.json({ error: statusResult.error.message }, { status: 500 })
   }
 
-  const recipients = await withTenant(tenantId, (client) =>
-    client.query<{ email: string }>(
-      `SELECT s.email FROM subscribers s
-       JOIN campaign_recipients cr ON cr.campaign_id = $1
-       WHERE (cr.list_id IS NULL OR s.list_id = cr.list_id)
-         AND s.status = 'active'`,
-      [params.id]
+  let recipients: { email: string }[]
+  try {
+    recipients = await withTenant(tenantId, (client) =>
+      client.query<{ email: string }>(
+        `SELECT s.email FROM subscribers s
+         JOIN campaign_recipients cr ON cr.campaign_id = $1
+         WHERE (cr.list_id IS NULL OR s.list_id = cr.list_id)
+           AND s.status = 'active'`,
+        [params.id]
+      )
     )
-  )
+  } catch (e) {
+    // Rollback auf draft — verhindert verwaisten 'sending'-Status
+    await updateCampaignStatus(tenantId, params.id, 'draft')
+    return NextResponse.json({ error: 'Empfänger konnten nicht geladen werden' }, { status: 500 })
+  }
 
-  // Suppression-Check PFLICHT — kein Opt-out-Empfänger darf in die Queue (Fix C3)
+  // Suppression-Check PFLICHT — kein Opt-out-Empfänger darf in die Queue
   const unsuppressedRecipients = await Promise.all(
     recipients.map(async (r) => {
       const suppressed = await checkSuppression(tenantId, r.email)
@@ -41,24 +47,30 @@ export async function POST(req: NextRequest, { params }: { params: { id: string
     })
   ).then((results) => results.filter((r): r is { email: string } => r !== null))
 
-  // Bulk-Enqueue — schnell, kein sequenzielles await (Fix C2)
-  const addedJobs = await emailSendQueue.addBulk(
-    unsuppressedRecipients.map((recipient) => ({
-      name: 'send',
-      data: {
-        tenantId,
-        campaignId: params.id,
-        recipientEmail: recipient.email,
-        recipientHash: hashEmail(recipient.email),
-      },
-      opts: {
-        attempts: 3,
-        backoff: { type: 'exponential' as const, delay: 2000 },
-        removeOnComplete: 100,
-        removeOnFail: { count: 500 },
-      },
-    }))
-  )
+  let addedJobs: { id?: string }[]
+  try {
+    addedJobs = await emailSendQueue.addBulk(
+      unsuppressedRecipients.map((recipient) => ({
+        name: 'send',
+        data: {
+          tenantId,
+          campaignId: params.id,
+          recipientEmail: recipient.email,
+          recipientHash: hashEmail(recipient.email),
+        },
+        opts: {
+          attempts: 3,
+          backoff: { type: 'exponential' as const, delay: 2000 },
+          removeOnComplete: 100,
+          removeOnFail: { count: 500 },
+        },
+      }))
+    )
+  } catch (e) {
+    // Rollback auf draft — Queue-Fehler darf nicht zu verwaisten Kampagnen führen
+    await updateCampaignStatus(tenantId, params.id, 'draft')
+    return NextResponse.json({ error: 'Jobs konnten nicht eingestellt werden' }, { status: 500 })
+  }
 
   return NextResponse.json({ queued: addedJobs.length })
 }