fix: close CPU profile file immediately on StartCPUProfile error

When pprof.StartCPUProfile fails, the file was left to be closed by
a deferred call placed before the error check. This could shadow the
original error and delay resource cleanup. Now the file is closed
explicitly on error, and defer is placed after the success path.

Fixes #1770
Fixes #1765

Assisted-By: cagent

Author: dgageot

cmd/root/run.go

@@ -142,11 +142,12 @@ func (f *runExecFlags) runOrExec(ctx context.Context, out *cli.Printer, args []s
 		if err != nil {
 			return fmt.Errorf("failed to create CPU profile: %w", err)
 		}
-		defer pf.Close()
 		if err := pprof.StartCPUProfile(pf); err != nil {
+			pf.Close()
 			return fmt.Errorf("failed to start CPU profile: %w", err)
 		}
 		defer pprof.StopCPUProfile()
+		defer pf.Close()
 		slog.Info("CPU profiling enabled", "file", f.cpuProfile)
 	}