R-415 fixed on hub main (no duplicate/nested/felhom.eu customer domain; R-138 option B); R-762 closed (9202 proven, catalog eec9a0d); R-905 opened (wger static in backups); decision sheet D10; 130 -> 129

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0159rPz1ZhFKsS53msqPYxtS

hub/internal/store/domain_conflict.go

@@ -0,0 +1,47 @@
+package store
+
+import "strings"
+
+// R-415 / R-138 option B (2026-10-08; operator ruling 2026-09-14, `01` §7: every customer has their OWN domain, never a
+// name under felhom.eu). The hub enforced uniqueness on customer_id only, so two customers could be given the same
+// domain — or one inside the other, a shared zone in all but name — silently. DomainConflict answers, for a domain about
+// to be saved for customerID, which rule it breaks ("" = none):
+//
+//   - "felhom.eu" — the domain is felhom.eu or a name under it;
+//   - "<other id>" — another customer's domain equals it, contains it, or lies under it.
+//
+// Matching is case-insensitive, ignores a trailing dot, and is on LABEL boundaries („notexample.hu" is not under
+// „example.hu"). An empty domain conflicts with nothing. Pinned by TestR415_* (domain_conflict_test.go) and the
+// handler test TestR415_CreateAndEditRefuseConflictingDomain.
+func (s *Store) DomainConflict(customerID, domain string) (string, error) {
+	d := normDomain(domain)
+	if d == "" {
+		return "", nil
+	}
+	if d == "felhom.eu" || strings.HasSuffix(d, ".felhom.eu") {
+		return "felhom.eu", nil
+	}
+	rows, err := s.db.Query(`SELECT customer_id, domain FROM customer_configs WHERE customer_id != ? AND domain != ''`, customerID)
+	if err != nil {
+		return "", err
+	}
+	defer rows.Close()
+	for rows.Next() {
+		var id, other string
+		if err := rows.Scan(&id, &other); err != nil {
+			return "", err
+		}
+		o := normDomain(other)
+		if o == "" {
+			continue
+		}
+		if d == o || strings.HasSuffix(d, "."+o) || strings.HasSuffix(o, "."+d) {
+			return id, nil
+		}
+	}
+	return "", rows.Err()
+}
+
+func normDomain(d string) string {
+	return strings.TrimSuffix(strings.ToLower(strings.TrimSpace(d)), ".")
+}