chore: initialize go module and fix cross-platform compilation issues

[ismailtsdln]

I have completed the task of reviewing and improving the gatt project. Below is a summary of the changes and verification steps taken.

• Linux Platform (linux/hci.go)
• Fixed trace function: Corrected variadic argument forwarding to log.Printf
• Fixed handleLEMeta: Resolved fmt.Errorf type mismatch
• Event Handling (linux/evt/evt.go)
• Added String() method: Improved log readability for LEEventCode enum
• macOS XPC Tests (xpc/xpc_darwin_test.go)
• Fixed compilation errors: Corrected invalid slice comparisons (UUID as []byte)
• Fixed undefined types: Replaced internal types (dict, array) with public types (Dict, Array)
• Added missing imports: Included reflect package for deep equality checks

✅ Verification

• Build Success: go test ./... passes across all packages
• Compilation: All previously failing files now compile correctly
• Platform Coverage: Linux and macOS-specific fixes applied