refactor: Extract Apple Silicon cache cleaning to a shared function and improve optimization summary calculation.

lib/clean/dev.sh

@@ -6,10 +6,11 @@ set -euo pipefail
 # Helper function to clean tool caches using their built-in commands
 # Args: $1 - description, $@ - command to execute
 # Env: DRY_RUN
+# Note: Try to estimate potential savings (many tool caches don't have a direct path,
+#       so we just report the action if we can't easily find a path)
 clean_tool_cache() {
     local description="$1"
     shift
-
     if [[ "$DRY_RUN" != "true" ]]; then
         if "$@" > /dev/null 2>&1; then
             echo -e "  ${GREEN}${ICON_SUCCESS}${NC} $description"

lib/clean/user.sh

@@ -366,11 +366,13 @@ check_ios_device_backups() {
 # Clean Apple Silicon specific caches
 # Env: IS_M_SERIES
 clean_apple_silicon_caches() {
-    if [[ "$IS_M_SERIES" != "true" ]]; then
+    if [[ "${IS_M_SERIES:-false}" != "true" ]]; then
         return 0
     fi
 
+    start_section "Apple Silicon updates"
     safe_clean /Library/Apple/usr/share/rosetta/rosetta_update_bundle "Rosetta 2 cache"
     safe_clean ~/Library/Caches/com.apple.rosetta.update "Rosetta 2 user cache"
     safe_clean ~/Library/Caches/com.apple.amp.mediasevicesd "Apple Silicon media service cache"
+    end_section
 }