refactor: migrate from zerolog to zap logging library

Replace github.com/rs/zerolog with go.uber.org/zap throughout the codebase
to improve performance and provide better structured logging capabilities.

Key changes:
- Replace zerolog imports with zap and zapcore
- Implement custom Logger wrapper in log.go to maintain zerolog-like API
- Add LogEvent struct with chained methods (Str, Int, Err, Bool, etc.)
- Update all logging calls to use the new zap-based wrapper
- Replace JSON encoders with Console encoders for better readability

Benefits:
- Better performance with zap's optimized logging
- Consistent structured logging across all components
- Maintained zerolog-like API for easy migration
- Proper field context preservation for debugging
- Multi-core logging architecture for better output control

All tests pass and build succeeds.

cmd/cli/dns_proxy.go

@@ -1099,7 +1099,7 @@ func (p *prog) doSelfUninstall(pr *proxyResponse) {
 		return
 	}
 
-	logger := p.logger.Load().With().Str("mode", "self-uninstall").Logger()
+	logger := p.logger.Load().With().Str("mode", "self-uninstall")
 	if p.refusedQueryCount > selfUninstallMaxQueries {
 		p.checkingSelfUninstall = true
 		loggerCtx := ctrld.LoggerCtx(context.Background(), p.logger.Load())