feat: email integration (nodemailer) + wire into agency/license flows

- src/lib/email.ts: SMTP client with pre-built templates:
  - sendAgencyApprovedEmail (reseller approval + discount)
  - sendAgencyRejectedEmail (reseller rejection + reason)
  - sendLicenseKeyEmail (license key delivery)
  - sendTicketCreatedEmail (ticket confirmation)
- Agency approve route: sends approval email after DB update
- Agency reject route: sends rejection email with reason
- License creation route: sends license key email (fire-and-forget)
- Graceful degradation: if SMTP not configured, logs warning + continues
- nodemailer + @types/nodemailer installed

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

@@ -304,6 +304,18 @@ export async function POST(req: Request) {
       },
     })
 
+    // Send license key email to the customer
+    const { sendLicenseKeyEmail } = await import('@/lib/email')
+    if (company.email && !parentId) {
+      // Only send for core licenses (not modules)
+      sendLicenseKeyEmail({
+        to: company.email,
+        licenseKey: key,
+        product,
+        plan,
+      }).catch(() => {}) // fire-and-forget, don't block response
+    }
+
     return NextResponse.json({ license, pricing: pricing.breakdown }, { status: 201 })
   } catch (err) {
     const msg = err instanceof Error ? err.message : 'internal server error'