Simplify exit cleanup to source single trace eraser script

Exit menu now tells user to SOURCE the trace eraser instead of running it as subprocess:
- Single command: TRACE_ERASER_AUTO=yes source tools/erase-toolkit-traces.sh
- Sourcing runs it in current shell, allowing it to modify that shell's history
- No more separate helper scripts or multiple steps
- Single source of truth for all cleanup logic

This fixes the parent shell history issue - by sourcing instead of running as subprocess, the trace eraser can actually modify the shell's history where the curl command was executed.

launcher.sh

@@ -1507,19 +1507,12 @@ main() {
                 read -p "Clean history and remove traces? (yes/no): " clean_hist
 
                 if [ "$clean_hist" = "yes" ]; then
-                    # Run the trace eraser in auto mode (removes files, logs, directory)
-                    TRACE_ERASER_AUTO=yes bash "$BASE_DIR/tools/erase-toolkit-traces.sh" 2>&1 | grep -E "^✓|^$" || true
-
-                    # Create a simple helper script for parent shell history cleanup
-                    # (Parent shell needs to source this since subprocess can't modify parent's history)
-                    cat > /tmp/.cleanup_hist.sh << 'HIST_EOF'
-set +o history; shopt -u histappend 2>/dev/null; GREP_PATTERN="git\.mull\.lol|linux-server-management-toolkit|server-toolkit|launcher\.sh|erase-toolkit-traces"; [ -f ~/.bash_history ] && cp ~/.bash_history ~/.bash_history.bak.$$ && grep -Ev "$GREP_PATTERN" ~/.bash_history.bak.$$ > ~/.bash_history 2>/dev/null && rm -f ~/.bash_history.bak.$$; history -c; history -r ~/.bash_history; unset HISTFILE; rm -f /tmp/.cleanup_hist.sh; echo ""; echo "✓ History cleaned"; echo ""
-HIST_EOF
-
                     echo ""
-                    echo -e "${GREEN}✓ All traces removed${NC}"
+                    echo -e "${YELLOW}After launcher exits, run:${NC}"
                     echo ""
-                    echo -e "${YELLOW}Run this to finish cleanup:${NC} source /tmp/.cleanup_hist.sh"
+                    echo "TRACE_ERASER_AUTO=yes source $BASE_DIR/tools/erase-toolkit-traces.sh"
+                    echo ""
+                    echo -e "${YELLOW}This will clean history in your current shell and remove all traces.${NC}"
                     echo ""
                 else
                     echo ""