WHOIS tool: allow IP address input (RIR/RDAP lookup)

Currently the WHOIS GUI only accepts domain names. Entering an IP address (e.g. 83.65.246.198) shows “Enter a valid Domain Name”, so IP WHOIS lookups are not possible.

Expected behavior
- Accept IPv4/IPv6 as valid input
- If input is an IP, perform a network/RIR lookup (RIPE/ARIN/APNIC/etc.), preferably via RDAP, and show allocation info (netblock/org/abuse)

Steps to reproduce
1. Open Tools -> WHOIS
2. Enter 83.65.246.198
3. Error: “Enter a valid Domain Name”

從 Tools -> WHOIS 畫面開始，追蹤網域名稱驗證與查詢的進入點。檢查目前的查詢如何顯示結果，然後將完成條件定義為接受 IPv4 與 IPv6 輸入、查詢適當的 RIR/RDAP 服務，並顯示配置、組織與濫用資訊。

由索引模型根據 Issue 內容生成。