docs(search): don't threshold JSON score as Tavily

S1: skill recipe now says result score is merged rank. Also send
non-zero --min-score to the server (N1), sort include_domains (N2),
and note that search_queries counts each sub-query (N3).

internal/search/filter.go

@@ -1,6 +1,7 @@
 package search
 
 import (
+	"sort"
 	"strings"
 	"time"
 	"unicode/utf8"
@@ -170,6 +171,7 @@ func normalizeDomains(in []string, hint string) ([]string, string) {
 	if len(out) == 0 {
 		return nil, ""
 	}
+	sort.Strings(out)
 	if len(out) > maxDomainList {
 		return nil, hint
 	}