feat/fix: Enhance stability and optimize performance for MSI Afterburner monitoring

[R0bles]

📝 Description

This PR introduces a series of critical stability fixes to prevent silent application crashes and implements several performance optimizations to reduce the system footprint. The main goal was to resolve OS-level Access Violations and improve the efficiency of the event-driven monitoring system.

🛠️ Technical Changes

Stability & Robustness

• Fixed Hard Crashes: Replaced dynamic syscall.NewCallback creation with a static global callback (enumCallback) in watcher/watcher.go to prevent memory instability and Access Violations.
• Panic Recovery: Added defer recover() blocks within Windows API callbacks to ensure that any internal panic is logged without terminating the entire process.
• Process Persistence: Implemented an "Idle Mode" in main.go, allowing the script to remain active even when MSI Afterburner is not running.

Performance & Resource Optimization

• Worker Pattern: Decoupled OS callbacks from processing logic using a channel-based worker pattern, improving responsiveness and stability.
• Throttling: Added event_throttle_ms to config.json and config/config.go to prevent CPU spikes during rapid window state changes. Testing showed that values between 200ms and 400ms are optimal for maintaining responsiveness without missing events; therefore, a default of 200ms was implemented.
• I/O Optimization: Implemented configuration caching to eliminate redundant disk reads during the main loop execution.

Debug

• Log Filtering: Reduced log spam by implementing a state-aware notification system for Afterburner detection.

🧪 How to Test

1. Stability Test: Run the application and open/close MSI Afterburner multiple times. The script should remain active (Idle Mode) and not crash.
2. Performance Test: Trigger rapid window changes (e.g., Alt-Tab frequently or open Task Manager). Prior to this fix, these actions caused severe CPU spikes with events triggering every ~30ms—an unacceptable overhead for a lightweight background utility. Monitor CPU usage to verify that event_throttle_ms now effectively limits these spikes.
3. Log Verification: Check the console output; "MSI Afterburner not detected" should only appear once per absence period.

✅ Checklist

• Fixed silent crashes (Access Violations).
• Implemented process persistence (Idle Mode).
• Reduced CPU and Disk I/O overhead.

🔗 Related Issue

• Closes Fix: Improve Application Stability and Performance (Hard Crash Prevention & Resource Optimization) #4