feat(hub): improve WHOIS lookup reliability and enhance site UI

Implement enhanced WHOIS lookup strategies, specifically targeting .eu
domains through EURid web scraping and alternative services to
improve data accuracy for expiry dates.

- Add EURid web scraping and alternative WHOIS service support for .eu domains
- Increase timeouts for .eu domain lookups in TCP and native WHOIS
- Improve domain scheduler to prevent overwriting valid data with zero-value dates
- Enhance site UI with subdomain indicators in domain tables
- Add filtering capabilities to the calendar view
- Implement drag-and-drop reordering for systems table
- Add new debug and test utilities for WHOIS and date parsing logic

test/date_parsing_demo.go

@@ -0,0 +1,94 @@
+package main
+
+import (
+	"fmt"
+	"regexp"
+	"strconv"
+)
+
+// parseFlexibleDate parses dates in various formats
+func parseFlexibleDate(dateString string) string {
+	if dateString == "" {
+		return ""
+	}
+	
+	// Remove common separators and normalize
+	normalized := regexp.MustCompile(`[./-]`).ReplaceAllString(dateString, "-")
+	normalized = regexp.MustCompile(`\s+`).ReplaceAllString(normalized, "")
+	
+	// Try different date formats
+	formats := []string{
+		// DD.MM.YYYY, DD/MM/YYYY, DD-MM-YYYY
+		`^(\d{2})[-/.](\d{2})[-/.](\d{4})$`,
+		// YYYY-MM-DD, YYYY/MM/DD, YYYY.MM.DD
+		`^(\d{4})[-/.](\d{2})[-/.](\d{2})$`,
+		// MM-DD-YYYY, MM/DD/YYYY, MM.DD.YYYY
+		`^(\d{2})[-/.](\d{2})[-/.](\d{4})$`,
+	}
+	
+	for _, format := range formats {
+		re := regexp.MustCompile(format)
+		match := re.FindStringSubmatch(normalized)
+		if match != nil {
+			part1, part2, part3 := match[1], match[2], match[3]
+			
+			// Determine if it's DD.MM.YYYY or YYYY.MM.DD format
+			var year, month, day string
+			
+			if len(part1) == 4 {
+				// YYYY.MM.DD format
+				year = part1
+				month = part2
+				day = part3
+			} else {
+				// DD.MM.YYYY format (most common)
+				day = part1
+				month = part2
+				year = part3
+			}
+			
+			// Validate and format
+			yearNum, _ := strconv.Atoi(year)
+			monthNum, _ := strconv.Atoi(month)
+			dayNum, _ := strconv.Atoi(day)
+			
+			if yearNum >= 2000 && yearNum <= 2100 && monthNum >= 1 && monthNum <= 12 && dayNum >= 1 && dayNum <= 31 {
+				return fmt.Sprintf("%s-%s-%s", year, fmt.Sprintf("%02s", month), fmt.Sprintf("%02s", day))
+			}
+		}
+	}
+	
+	return ""
+}
+
+func main() {
+	testDates := []string{
+		"15.06.2026",
+		"13.11.2029",
+		"2026-06-15",
+		"15/06/2026",
+		"13-11-2029",
+		"2026.06.15",
+		"15 06 2026",
+		"invalid-date",
+		"32.13.2026", // Invalid day/month
+		"1999.12.31", // Too old
+	}
+	
+	fmt.Println("Testing Flexible Date Parsing")
+	fmt.Println("=============================")
+	
+	for _, date := range testDates {
+		result := parseFlexibleDate(date)
+		status := "✅"
+		if result == "" {
+			status = "❌"
+		}
+		fmt.Printf("%s '%s' -> '%s'\n", status, date, result)
+	}
+	
+	fmt.Println("\nExample Usage:")
+	fmt.Println("=============")
+	fmt.Println("User can paste: '15.06.2026, 13.11.2029'")
+	fmt.Println("System will parse: '2026-06-15', '2029-11-13'")
+}