fix: Add cross-platform handling for tray, updater, and icon generation

- Add platform notes for tray startup, shortcut saving, and Linux-only settings
- Handle stat error in processRecording (missing file)
- Select correct binary name based on OS in updater
- Increase tray icon canvas size from 64 to 128 pixels
- Update frontend dist asset hash

internal/windows/process.go

@@ -1,4 +1,12 @@
 //go:build windows
+
+// ============================================================
+// WINDOWS-ONLY FILE — Windows process management utilities.
+// Uses Win32 API (OpenProcess, GetExitCodeProcess) to check
+// if a process is running. The Linux equivalent for process
+// checking is in internal/linux/process.go
+// ============================================================
+
 package windows
 
 import (