fix(mihomo): restore the Steam community and store PROXY rules (#412)

The comment trim dropped them. Without a domain rule above the Valve IP ranges,
steamcommunity.com and steampowered.com match those ranges and go DIRECT.

modules/nixos/desktop/networking/mihomo/policy.yaml

@@ -70,6 +70,8 @@ rules:
   - DOMAIN-SUFFIX,steamserver.net,DIRECT
   - DOMAIN-SUFFIX,steam-chat.com,DIRECT
   - DOMAIN-SUFFIX,steamcontent.com,DIRECT
+  - DOMAIN-SUFFIX,steamcommunity.com,PROXY
+  - DOMAIN-SUFFIX,steampowered.com,PROXY
   # Steam's mainland CDN partners. Not `manlaxy.com`: Valve's worldwide store/CDN
   # domain, so pinning it DIRECT would break a proxied store.
   - DOMAIN-SUFFIX,clngaa.com,DIRECT