feat: create mailgun-webhook workspace

Initialize empty workspace for Mailgun webhook handler service
- Processes email verification and status updates
- Communicates with web-app via shared MongoDB
- Handles Mailgun webhook events

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

mailgun-webhook/README.md

@@ -0,0 +1,23 @@
+# Mailgun Webhook Handler
+
+This workspace contains the Mailgun webhook handler service for processing email events related to the Evidencija Režija tenant notification system.
+
+## Purpose
+
+This service handles email verification and status updates by:
+- Detecting new tenant email addresses (EmailStatus.Unverified)
+- Sending verification emails via Mailgun
+- Updating email status to VerificationPending
+- Processing webhook events from Mailgun (bounces, complaints, etc.)
+
+## Architecture
+
+This is a separate system from the Next.js web-app that communicates via the shared MongoDB database.
+
+## Setup
+
+TBD
+
+## Environment Variables
+
+TBD