Batch 3: Reorganize GFW area to Network & VPN

- Rename GFW/ → Network & VPN/ (clearer naming)
- Rename Bills.md → VPN-Subscriptions.md (more descriptive)
- Move Clash热点升级.md → Resources/Development/Tools/clash-hotspot-upgrade.md
- Create Network & VPN.md hub file with dataview query
- Add standard frontmatter to hub file

(vault changes by Claude Code)

200-area/Network & VPN/Network & VPN.md

@@ -0,0 +1,13 @@
+---
+title: Network & VPN
+type: area-hub
+tags: [area, para, network, vpn]
+created: 2025-12-29
+updated: 2025-12-29
+---
+
+### Notes
+```dataview
+table file.ctime as Date from "200-area/Network & VPN"
+sort file.name
+```