fix(security): prevent integer overflow in uint64 to int64 conversions

Add overflow checks before converting uint64 memory values to int64
to prevent potential integer overflow issues identified by gosec (G115).

- Add math.MaxInt64 checks in fileproc/backpressure.go
- Add math.MaxInt64 checks in fileproc/resource_monitor_validation.go
- Add math.MaxInt64 checks in fileproc/resource_monitor_metrics.go
- Add math.MaxInt64 check in benchmark/benchmark.go with nosec annotation

Co-authored-by: ivuorinen <11024+ivuorinen@users.noreply.github.com>

cli/processor_workers.go

@@ -82,4 +82,4 @@ func (p *Processor) waitForCompletion(wg *sync.WaitGroup, writeCh chan fileproc.
 	wg.Wait()
 	close(writeCh)
 	<-writerDone
-}
+}