v1.25: Fix menu color rendering and clarify COTURN is optional

Fixes:
- Add -e flag to echo statements so BOLD and CYAN colors render properly
- Previously showed raw escape codes like \033[1m instead of formatted text

Clarifications:
- Changed "Full Setup" description from "With FQDN, TLS certs, COTURN, internet calling"
  to "Optionally add FQDN, TLS certs, COTURN for internet calling"
- COTURN is NOT mandatory in Full Setup
- It's only configured if user runs Internet/Certificate Setup wizard afterward

User can now see properly formatted menu:
  1) Quick Local Setup (Recommended)  [in bold]
     └─ Local LAN only - PTT, auto-answer, no internet/FQDN

  Advanced Options: [in cyan]
  2) Full Setup (Server + Client + Internet)
     └─ Optionally add FQDN, TLS certs, COTURN for internet calling

easy-asterisk-interactive-v1.25.sh

@@ -3072,12 +3072,12 @@ show_main_menu() {
 submenu_install() {
     clear
     print_header "Install"
-    echo "  ${BOLD}1) Quick Local Setup (Recommended)${NC}"
+    echo -e "  ${BOLD}1) Quick Local Setup (Recommended)${NC}"
     echo "     └─ Local LAN only - PTT, auto-answer, no internet/FQDN"
     echo ""
-    echo "  ${CYAN}Advanced Options:${NC}"
+    echo -e "  ${CYAN}Advanced Options:${NC}"
     echo "  2) Full Setup (Server + Client + Internet)"
-    echo "     └─ With FQDN, TLS certs, COTURN, internet calling"
+    echo "     └─ Optionally add FQDN, TLS certs, COTURN for internet calling"
     echo "  3) Server Only"
     echo "     └─ Just Asterisk server (optionally with FQDN/internet)"
     echo "  4) Client Only"