Auto-Register in Task Scheduler on First Run #1

The app should automatically register itself as a scheduled task on first launch. Subsequent runs skip registration.
Acceptance Criteria

• On first run, create a task via schtasks /Create (trigger: e.g. every 6h or on logon).
• If the task already exists, do nothing.
• The task must be configured to run with highest privileges (/RL HIGHEST).
• If the EXE path changes, update the task on next manual run.