feat: instance admin login token + cleanup cron (GitHub Action)

Instance admin login:
- Provisioning generates adminLoginToken (crypto random, 7-day expiry)
- Sends instance-ready email with admin login URL to customer
- Token returned in provisioning response

Cleanup cron:
- .github/workflows/cleanup-cron.yml: daily at 03:00 UTC
- Calls POST /api/aos/instances/cleanup with CRON_SECRET
- Also supports manual trigger (workflow_dispatch)
- Requires GitHub secrets: AOS_URL, CRON_SECRET

src/app/api/aos/instances/route.ts

@@ -253,6 +253,20 @@ export async function POST(req: Request) {
         },
       })
 
+      // --- Generate admin login token (one-time, 7-day expiry) ---
+      // This token allows the client to access their instance admin panel
+      // without separate credentials. Sent via email (if SMTP configured).
+      const crypto = await import('crypto')
+      const adminToken = `admin-${crypto.randomBytes(24).toString('hex')}`
+      const adminTokenExpires = new Date(Date.now() + 7 * 86400000)
+      await db.instance.update({
+        where: { id: instance.id },
+        data: {
+          adminLoginToken: adminToken,
+          adminLoginExpiresAt: adminTokenExpires,
+        },
+      })
+
       // --- Graphify: trigger background graph build ---
       // Builds a knowledge graph from the instance's Git repo so the support
       // ticket AI can query the codebase later. Fire-and-forget: we don't
@@ -295,12 +309,26 @@ export async function POST(req: Request) {
         },
       })
 
+      // Send instance ready email with admin login link
+      const { sendEmail } = await import('@/lib/email')
+      if (company.email) {
+        const adminLoginUrl = `${result.url}/?admin_token=${adminToken}`
+        sendEmail({
+          to: company.email,
+          subject: `Ihre ${product}-Instanz ist bereit — ${result.url}`,
+          text: `Guten Tag,\n\nIhre Instanz wurde erfolgreich bereitgestellt.\n\nURL: ${result.url}\nAdmin-Login: ${adminLoginUrl}\n${isDemo ? `Demo-Laufzeit: 14 Tage (endet am ${new Date(instance.demoExpiresAt!).toLocaleDateString('de-DE')})` : ''}\n\nMit freundlichen Grüßen\nDFM Solutions`,
+          html: `<p>Guten Tag,</p><p>Ihre <strong>${product}</strong>-Instanz wurde erfolgreich bereitgestellt.</p><p><strong>URL:</strong> <a href="${result.url}">${result.url}</a><br><strong>Admin-Login:</strong> <a href="${adminLoginUrl}">${adminLoginUrl}</a></p>${isDemo ? `<p><strong>Demo-Laufzeit:</strong> 14 Tage (endet am ${new Date(instance.demoExpiresAt!).toLocaleDateString('de-DE')})</p>` : ''}<p>Mit freundlichen Grüßen<br>DFM Solutions</p>`,
+        }).catch(() => {})
+      }
+
       return NextResponse.json({
         instanceId: instance.id,
         subdomain,
         url: result.url,
         status: isDemo ? 'demo_active' : 'active',
         demoExpiresAt: instance.demoExpiresAt,
+        adminLoginToken: adminToken,
+        adminLoginUrl: `${result.url}/?admin_token=${adminToken}`,
       }, { status: 201 })
     } catch (provErr) {
       // Provisioning failed — mark as failed, keep the record for retry