feat: add mihomo default config and as-default module

modules/mihomo-as-default/files/etc/hotplug.d/iface/99-mihomo

@@ -0,0 +1,26 @@
+#!/bin/sh
+
+echo "iface $INTERFACE $ACTION detected..."
+
+[ "$ACTION" = "ifup" -a "$INTERFACE" = "wan" ] && {
+
+    sleep 3
+
+    ps | grep mihomo | grep nobody
+    if [ $? -eq 0 ]; then
+        logger "mihomo is running"
+    else
+        if [ ! -f /root/.mihomo_first_boot ]; then
+            logger "First boot detected, starting mihomo..."
+
+            uci -q set mihomo.config.enabled=1
+            uci -q commit mihomo
+
+            /etc/init.d/mihomo start
+
+            touch /root/.mihomo_first_boot
+        else
+            logger "Not first boot, mihomo start according to config"
+        fi
+    fi
+}

modules/openwrt-mihomo/example.env

@@ -0,0 +1 @@
+CLASH_CONFIG_URL=https://a.com/config.yml

modules/openwrt-mihomo/files/etc/uci-defaults/99-mihomo

@@ -0,0 +1,13 @@
+uci batch << EOF
+set mihomo.config.fast_reload='0'
+set mihomo.proxy.tcp_transparent_proxy_mode='tproxy'
+set mihomo.proxy.udp_transparent_proxy_mode='tproxy'
+set mihomo.proxy.ipv6_proxy='1'
+set mihomo.proxy.bypass_china_mainland_ip='1'
+set mihomo.subscription.url='$CLASH_CONFIG_URL'
+set mihomo.mixin.ipv6='1'
+set mihomo.mixin.dns_mode='normal'
+set mihomo.mixin.dns_ipv6='1'
+set mihomo.mixin.dns_system_hosts='1'
+commit
+EOF