fix(purge): parallelize size calculations to prevent hang (issue #560)

Sequential du calls with 15s timeout each meant N artifacts × 15s of potential
wait when paths are on slow storage (network mounts, Syncthing, large dirs).
Now all du processes are launched concurrently; total time is bounded by the
single longest call (≤ 15s) rather than N × 15s.

fix(protection): protect CoreAudio paths in should_protect_path (issue #553)

Add com.apple.coreaudio*, com.apple.audio.*, and coreaudiod* to the protected
path patterns so deep-clean cannot touch audio subsystem caches, reducing risk
of audio output loss on Intel Macs running macOS Sequoia.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

lib/core/app_protection.sh

@@ -810,6 +810,11 @@ should_protect_path() {
         */Library/Mobile\ Documents* | */Mobile\ Documents*)
             return 0
             ;;
+        # CoreAudio and audio subsystem caches (issue #553)
+        # Cleaning these can cause audio output loss on Intel Macs
+        *com.apple.coreaudio* | *com.apple.audio.* | *coreaudiod*)
+            return 0
+            ;;
     esac
 
     # 6. Match full path against protected patterns