fix(felhom-wipe): nuclear wipe stops early due to set -e + missing state files

[ -f "$f" ] && rm -f "$f" && info "..." returns exit code 1 when the
file doesn't exist, triggering set -euo pipefail. Nuclear wipe was
silently stopping after settings.json and metrics.db (the only two
state files present), never reaching the controller/full/nuclear steps.

Fix: if [ -f "$f" ]; then rm -f "$f" && info "..."; fi

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

scripts/felhom-wipe.sh

@@ -346,7 +346,7 @@ do_soft_wipe() {
     info "Soft wipe: removing controller state..."
     local state_files=("$DATA_DIR/settings.json" "$DATA_DIR/metrics.db" "$DATA_DIR/setup-state.json" "$DATA_DIR/update-state.json" "$DATA_DIR/session-data.json" "$DATA_DIR/snapshot-history.json")
     for f in "${state_files[@]}"; do
-        [ -f "$f" ] && rm -f "$f" && info "  Removed: $f"
+        if [ -f "$f" ]; then rm -f "$f" && info "  Removed: $f"; fi
     done
 }