fix: remove redundant pipefail blocks and fix arithmetic bug

This commit addresses the issue #506 where mole would exit prematurely
during application support scanning.

Changes:
1. Remove 4 redundant pipefail disable/restore blocks:
   - safe_find_delete() in lib/core/file_ops.sh
   - safe_sudo_find_delete() in lib/core/file_ops.sh
   - fix_broken_preferences() in lib/optimize/maintenance.sh
   - opt_saved_state_cleanup() in lib/optimize/tasks.sh

   These were unnecessary because process substitution (< <(cmd)) is not
   affected by pipefail - only real pipelines (cmd1 | cmd2) are.

2. Fix real bug in fix_broken_preferences():
   - Add || true to ((broken_count++)) on lines 35 and 55
   - This prevents set -e from exiting when broken_count starts at 0

Fixes #506

lib/optimize/tasks.sh

@@ -191,24 +191,12 @@ opt_saved_state_cleanup() {
     local state_dir="$HOME/Library/Saved Application State"
 
     if [[ -d "$state_dir" ]]; then
-        # Temporarily disable pipefail to prevent process substitution failures from interrupting
-        local pipefail_was_set=false
-        if [[ -o pipefail ]]; then
-            pipefail_was_set=true
-            set +o pipefail
-        fi
-
         while IFS= read -r -d '' state_path; do
             if should_protect_path "$state_path"; then
                 continue
             fi
             safe_remove "$state_path" true > /dev/null 2>&1 || true
         done < <(command find "$state_dir" -type d -name "*.savedState" -mtime "+$MOLE_SAVED_STATE_AGE_DAYS" -print0 2> /dev/null)
-
-        # Restore pipefail if it was previously set
-        if [[ "$pipefail_was_set" == "true" ]]; then
-            set -o pipefail
-        fi
     fi
 
     opt_msg "App saved states optimized"