fix: address code review findings (HIGH + MEDIUM)

- Replace GNU \b with portable word-boundary sed patterns in kernel-params
- Warn on unknown CLI arguments instead of silently swallowing
- Add floor check on recommended_gttsize_mib to prevent negative values
- Fix Python operator precedence in benchmark log parser
- Add root checks to tuned-profile.sh and rollback.sh
- Remove redundant sudo calls (scripts already require root at entry)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

scripts/monitor/dashboard.sh

@@ -13,7 +13,7 @@ while [[ $# -gt 0 ]]; do
     case "$1" in
         --simple|-s) SIMPLE=true; shift ;;
         --with-logging|-l) WITH_LOG=true; shift ;;
-        *) shift ;;
+        *) log_warn "Unknown argument: $1"; shift ;;
     esac
 done