feat(dns): Add real-time DNS speed benchmark and 'Fastest' auto-selection option (#4935)

* feat(dns): Add real-time DNS speed benchmark and 'Fastest' auto-selection option

* fix(dns): Address CodeRabbit & Codex PR review feedback

* fix(ci): Remove .biomeignore to keep repository root clean

* Fix Fastest DNS eligibility and failed probe handling

---------

Co-authored-by: Chris Titus <contact@christitus.com>

config/dns.json

@@ -1,5 +1,6 @@
 {
     "Google":{
+        "BenchmarkEligible": true,
         "Primary": "8.8.8.8",
         "Secondary": "8.8.4.4",
         "Primary6": "2001:4860:4860::8888",
@@ -7,6 +8,7 @@
         "DohTemplate": "https://dns.google/dns-query"
     },
     "Cloudflare":{
+        "BenchmarkEligible": true,
         "Primary": "1.1.1.1",
         "Secondary": "1.0.0.1",
         "Primary6": "2606:4700:4700::1111",

config/tweaks.json

@@ -1885,7 +1885,7 @@
     "category": "z__Advanced Tweaks - CAUTION",
     "panel": "1",
     "Type": "Combobox",
-    "ComboItems": "Default DHCP Google Cloudflare Cloudflare_Malware Cloudflare_Malware_Adult Open_DNS Quad9 AdGuard_Ads_Trackers AdGuard_Ads_Trackers_Malware_Adult",
+    "ComboItems": "Default DHCP Fastest Google Cloudflare Cloudflare_Malware Cloudflare_Malware_Adult Open_DNS Quad9 AdGuard_Ads_Trackers AdGuard_Ads_Trackers_Malware_Adult",
     "link": "https://winutil.christitus.com/code-reference/tweaks/z--advanced-tweaks---caution/changedns"
   },
   "WPFAddUltPerf": {