A5: Extract all route groups into Flask blueprints (app.py -1735 lines)

Extract 9 route groups out of app.py into routes/ blueprints:
- routes/network.py  — DNS, DHCP, NTP, network info/test (10 routes)
- routes/wireguard.py — WireGuard keys, peers, config, enforcement (18 routes)
- routes/cells.py    — cell-to-cell connections (5 routes)
- routes/peers.py    — peer CRUD + IP update + _next_peer_ip helper (10 routes)
- routes/routing.py  — NAT, peer routes, firewall, iptables (17 routes)
- routes/vault.py    — certs, trust, secrets (19 routes)
- routes/containers.py — containers, images, volumes (14 routes)
- routes/services.py — service bus, logs, services status/connectivity (18 routes)
- routes/peer_dashboard.py — peer-scoped dashboard/services (2 routes)

All blueprints use lazy `from app import X` inside route bodies to preserve
test patch compatibility (patch('app.email_manager', mock) still works).

Also included in this commit:
- A1 fix: backup/restore now includes email/calendar user files
- A2 fix: apply_config sets applying=True flag via helper container
- A3 fix: add_peer rolls back firewall on DNS failure

app.py reduced: 3011 → 1294 lines. 1021 tests passing.

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

api/routes/email.py

@@ -0,0 +1,92 @@
+import logging
+from flask import Blueprint, request, jsonify
+logger = logging.getLogger('picell')
+bp = Blueprint('email', __name__)
+
+@bp.route('/api/email/users', methods=['GET'])
+def get_email_users():
+    """Get email users."""
+    try:
+        from app import email_manager
+        users = email_manager.get_users()
+        return jsonify(users)
+    except Exception as e:
+        logger.error(f"Error getting email users: {e}")
+        return jsonify({"error": str(e)}), 500
+
+@bp.route('/api/email/users', methods=['POST'])
+def create_email_user():
+    """Create email user."""
+    try:
+        from app import email_manager, _configured_domain
+        data = request.get_json(silent=True)
+        if data is None:
+            return jsonify({"error": "No data provided"}), 400
+        username = data.get('username')
+        domain = data.get('domain') or _configured_domain()
+        password = data.get('password')
+        if not username or not password:
+            return jsonify({"error": "Missing required fields: username, password"}), 400
+        result = email_manager.create_email_user(username, domain, password)
+        return jsonify({"created": result})
+    except Exception as e:
+        logger.error(f"Error creating email user: {e}")
+        return jsonify({"error": str(e)}), 500
+
+@bp.route('/api/email/users/<username>', methods=['DELETE'])
+def delete_email_user(username):
+    """Delete email user."""
+    try:
+        from app import email_manager, _configured_domain
+        domain = request.args.get('domain') or _configured_domain()
+        result = email_manager.delete_email_user(username, domain)
+        return jsonify({"deleted": result})
+    except Exception as e:
+        logger.error(f"Error deleting email user: {e}")
+        return jsonify({"error": str(e)}), 500
+
+@bp.route('/api/email/status', methods=['GET'])
+def get_email_status():
+    """Get email service status."""
+    try:
+        from app import email_manager
+        status = email_manager.get_status()
+        return jsonify(status)
+    except Exception as e:
+        logger.error(f"Error getting email status: {e}")
+        return jsonify({"error": str(e)}), 500
+
+@bp.route('/api/email/connectivity', methods=['GET'])
+def test_email_connectivity():
+    """Test email connectivity."""
+    try:
+        from app import email_manager
+        result = email_manager.test_connectivity()
+        return jsonify(result)
+    except Exception as e:
+        logger.error(f"Error testing email connectivity: {e}")
+        return jsonify({"error": str(e)}), 500
+
+@bp.route('/api/email/send', methods=['POST'])
+def send_email():
+    try:
+        from app import email_manager
+        data = request.get_json(silent=True)
+        if data is None:
+            return jsonify({"error": "No data provided"}), 400
+        result = email_manager.send_email(data)
+        return jsonify(result)
+    except Exception as e:
+        logger.error(f"Error sending email: {e}")
+        return jsonify({"error": str(e)}), 500
+
+@bp.route('/api/email/mailbox/<username>', methods=['GET'])
+def get_mailbox_info(username):
+    """Get mailbox information."""
+    try:
+        from app import email_manager
+        result = email_manager.get_mailbox_info(username)
+        return jsonify(result)
+    except Exception as e:
+        logger.error(f"Error getting mailbox info: {e}")
+        return jsonify({"error": str(e)}), 500