feat: add Yggdrasil overlay network to firmware build

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

files/etc/uci-defaults/99-parahub-mesh

@@ -374,7 +374,33 @@ SYS_EOF
 uci commit system
 
 # ============================================================================
-# 10. FINAL
+# 10. YGGDRASIL OVERLAY NETWORK
+# ============================================================================
+
+# Generate unique keys for this node
+yggdrasil -genconf | sed 's/IfName: .*/IfName: ygg0/' > /etc/yggdrasil.conf
+
+# UCI network interface for yggdrasil TUN
+uci batch <<-YGG_EOF
+set network.yggdrasil=interface
+set network.yggdrasil.device='ygg0'
+set network.yggdrasil.proto='none'
+YGG_EOF
+uci commit network
+
+# Add yggdrasil to LAN zone (mesh nodes trust each other)
+uci add_list firewall.@zone[0].network='yggdrasil'
+uci commit firewall
+
+# Enable yggdrasil service
+/etc/init.d/yggdrasil enable
+
+# Save yggdrasil address to node keys file
+YGG_ADDR=$(yggdrasil -address -useconffile /etc/yggdrasil.conf 2>/dev/null || echo "unknown")
+echo "YGGDRASIL_ADDRESS=${YGG_ADDR}" >> /etc/parahub/keys
+
+# ============================================================================
+# 11. FINAL
 # ============================================================================
 
 # Log completion
@@ -383,5 +409,6 @@ logger -t parahub-mesh "Hostname: ${HOSTNAME}"
 logger -t parahub-mesh "Private: ${PRIVATE_SSID} @ ${PRIV_IP}/24"
 logger -t parahub-mesh "Guest: ${PUBLIC_SSID} @ ${GUEST_IP}/24"
 logger -t parahub-mesh "Mesh ID: ${MESH_ID}"
+logger -t parahub-mesh "Yggdrasil: ${YGG_ADDR}"
 
 exit 0

scripts/build.sh

@@ -58,6 +58,9 @@ PACKAGES_CORE=(
     wpad-mesh-mbedtls
     -wpad-basic-mbedtls
 
+    # Yggdrasil overlay network
+    yggdrasil
+
     # SQM traffic shaping
     sqm-scripts
     kmod-sched-cake