HyAnnouncer - Announcements - Broadcasts - Sounds

Using fresh configs will be good for everyone!
Structures and usages changed.

### 1. Scheduled Actions System
- Added cron-based scheduling with support for 5-field cron expressions
- Added simple mode with duration strings (10s, 5m, 1h, 2d)
- Created ScheduledActionsConfig for scheduled-actions.json
- Created ScheduledActionManager to handle cron and duration-based scheduling
- Announcements in scheduled-actions are automatically excluded from rotation
- Support for multiple schedules per announcement ID
- Validation and error handling with GUI warnings for invalid actions
- Default examples: scheduled_title1 (5m) and scheduled_daily_title (daily at noon)

### 2. Sound System
- Created SoundUtil for playing sounds to players
- Added Sound field to all announcement configs:
- Chat announcements: default empty
- Title announcements: default "SFX_Rope_Break"
- Notification announcements: default "SFX_Rope_Break"
- Integrated sound playback into all announcement types
- Scheduled actions can override announcement sounds

### 3. Advanced Lag Protection
- Added minimum gap protection (1.5 seconds) to all announcement managers
- Smart skip logic prevents announcement bursts during server lag
- Global coordination across all announcement types

### 4. GUI Enhancements
- Created ScheduledActionsGui with full management interface
- Added "Scheduled Actions" button to main index (row 1, next to Join-Leave)
- Updated announcement GUIs to show "Scheduled" status for scheduled announcements
- Scheduled announcements display schedule instead of interval
- Start/Stop buttons hidden for scheduled announcements
- Added orange "Scheduled" status label to all announcement entry UIs