fix: don't clear screen in non-interactive mode

Problem:
- When running 'curl ... | bash -s core' the screen would clear
- This made it appear like nothing was happening after preview
- Users couldn't see the installation progress

Solution:
- Only call 'clear' in interactive mode
- Skip clear when NON_INTERACTIVE=true
- Allows users to see full output when piped from curl

Now users can see:
- Dependency checks
- Registry fetch
- Installation preview
- 'Installing automatically' message
- Full installation progress
- Completion message

This makes the installation process transparent and debuggable.

install.sh

@@ -455,7 +455,10 @@ show_component_selection() {
 #############################################################################
 
 show_installation_preview() {
-    clear
+    # Only clear screen in interactive mode
+    if [ "$NON_INTERACTIVE" != true ]; then
+        clear
+    fi
     print_header
     
     echo -e "${BOLD}Installation Preview${NC}\n"