Add egglocke, wonderlocke, and randomizer variant rules

When any variant rule is enabled, the encounter modal switches from
the game's regional dex to an all-Pokemon search (same debounced
API pattern as EggEncounterModal). A new "Run Variant" section in
rules configuration groups these rules, and badges render in amber.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/src/components/RuleBadges.tsx

@@ -21,7 +21,9 @@ export function RuleBadges({ rules }: RuleBadgesProps) {
           className={`px-2 py-0.5 rounded-full text-xs font-medium ${
             def.category === 'core'
               ? 'bg-blue-900/40 text-blue-300 light:bg-blue-100 light:text-blue-700'
-              : 'bg-purple-900/40 text-purple-300 light:bg-purple-100 light:text-purple-700'
+              : def.category === 'variant'
+                ? 'bg-amber-900/40 text-amber-300 light:bg-amber-100 light:text-amber-700'
+                : 'bg-purple-900/40 text-purple-300 light:bg-purple-100 light:text-purple-700'
           }`}
         >
           {def.name}