feat(lns): parse dns= records from alias comments as fallback

- When HSD sidechain returns null for a name, fall back to parsing
  dns= field from the main chain alias comment
- Format: dns=A:@:1.2.3.4,CNAME:www:lthn.io,TXT:@:value
- ParseDNSFromComment extracts records and adds to cache
- Names registered via Blesta now resolve through LNS
- Always sync (removed tree root skip) to catch new alias comments

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

cmd/lns/discovery.go

@@ -98,6 +98,79 @@ func getChainAliases() []ChainAlias {
 	return aliases
 }
 
+// ParseDNSFromComment extracts DNS records from an alias comment's dns= field.
+// Format: dns=A:@:1.2.3.4,AAAA:@:2001:db8::1,CNAME:www:lthn.io
+//
+//	records := ParseDNSFromComment("v=lthn1;type=user;dns=A:@:10.69.69.165,TXT:@:hello")
+func ParseDNSFromComment(comment string) *NameRecord {
+	parsed := parseAliasComment(comment)
+	dnsField, hasDNS := parsed["dns"]
+	if !hasDNS || dnsField == "" {
+		return nil
+	}
+
+	record := &NameRecord{}
+	entries := splitComma(dnsField)
+	for _, entry := range entries {
+		parts := splitColon(entry, 3)
+		if len(parts) < 3 {
+			continue
+		}
+		recordType := parts[0]
+		value := parts[2]
+		switch recordType {
+		case "A":
+			record.A = append(record.A, value)
+		case "AAAA":
+			record.AAAA = append(record.AAAA, value)
+		case "CNAME":
+			record.A = append(record.A, value) // CNAME stored as A for resolution
+		case "TXT":
+			record.TXT = append(record.TXT, value)
+		case "NS":
+			record.NS = append(record.NS, value)
+		}
+	}
+	if len(record.A) == 0 && len(record.AAAA) == 0 && len(record.TXT) == 0 && len(record.NS) == 0 {
+		return nil
+	}
+	return record
+}
+
+func splitComma(input string) []string {
+	parts := make([]string, 0)
+	current := ""
+	for _, character := range input {
+		if character == ',' {
+			if current != "" {
+				parts = append(parts, current)
+			}
+			current = ""
+		} else {
+			current += string(character)
+		}
+	}
+	if current != "" {
+		parts = append(parts, current)
+	}
+	return parts
+}
+
+func splitColon(input string, maxParts int) []string {
+	parts := make([]string, 0, maxParts)
+	current := ""
+	for _, character := range input {
+		if character == ':' && len(parts) < maxParts-1 {
+			parts = append(parts, current)
+			current = ""
+		} else {
+			current += string(character)
+		}
+	}
+	parts = append(parts, current)
+	return parts
+}
+
 // parseAliasComment extracts key=value pairs from a v=lthn1 alias comment.
 //
 //	parseAliasComment("v=lthn1;type=gateway;cap=vpn,dns")

cmd/lns/main.go

@@ -121,18 +121,57 @@ var knownNames = []string{
 
 func syncCache() {
 	root := getTreeRoot()
-	if root == lastRoot && root != "" {
-		return
-	}
 
 	// Discover names from the main chain, fall back to hardcoded list.
-	names := discoverNames()
+	aliases := getChainAliases()
+	names := make([]string, 0)
+	aliasMap := make(map[string]ChainAlias)
 
-	core.Println(core.Sprintf("[%s] Tree root changed — syncing %d names", time.Now().Format("15:04:05"), len(names)))
+	if len(aliases) > 0 {
+		seen := make(map[string]bool)
+		for _, alias := range aliases {
+			hnsName := alias.Name
+			comment := parseAliasComment(alias.Comment)
+			if hns, ok := comment["hns"]; ok && hns != "" {
+				stripped := core.TrimSuffix(hns, ".lthn")
+				if stripped != "" {
+					hnsName = stripped
+				}
+			}
+			if !seen[hnsName] {
+				seen[hnsName] = true
+				names = append(names, hnsName)
+				aliasMap[hnsName] = alias
+			}
+		}
+	} else {
+		names = knownNames
+	}
+
+	dnsCount := 0
+	for _, a := range aliases { if core.Contains(a.Comment, "dns=") { dnsCount++ } }
+	core.Println(core.Sprintf("[%s] Syncing %d names (%d with dns=, %d in aliasMap)", time.Now().Format("15:04:05"), len(names), dnsCount, len(aliasMap)))
 	for _, name := range names {
+		// Try HSD sidechain first
 		record := getNameRecords(name)
 		if record != nil {
 			cache[name] = record
+			continue
+		}
+
+		// Fall back to dns= entries in alias comment
+		if alias, exists := aliasMap[name]; exists && core.Contains(alias.Comment, "dns=") {
+			record = ParseDNSFromComment(alias.Comment)
+			core.Println(core.Sprintf("[dns=] %s comment=%s record=%v", name, alias.Comment, record != nil))
+			if record != nil {
+				record.Name = name
+				// Add the TXT metadata from the comment itself
+				comment := alias.Comment
+				if comment != "" && len(record.TXT) == 0 {
+					record.TXT = append(record.TXT, comment)
+				}
+				cache[name] = record
+			}
 		}
 	}
 	lastRoot = root