Fix remote exec ignoring --detach-keys option

The remote client completely ignores the --detach-keys option for exec
sessions. The ExecStartAndAttach() function in pkg/bindings/containers/attach.go
hardcodes empty detach keys ([]byte{}) instead of using the detach keys
stored in the exec session configuration.

This prevents users from detaching from exec sessions using custom key
sequences, making the --detach-keys option ineffective.

This commit fixes the issue by:
1. Extracting detach keys from the exec session after inspection
2. Parsing them using term.ToBytes() (unless empty string)
3. Using the parsed keys in both detach.Copy() calls

The fix maintains backward compatibility:
- Exec sessions without detach keys -> empty string -> []byte{} (unchanged)
- Empty detach keys (--detach-keys="") -> empty string -> []byte{} (correct)
- Custom detach keys -> parsed and used (new functionality)

Related to PR #25083 and issue #25089 which track comprehensive detach
key functionality. A proper interactive test for detach behavior exists
in test/system/450-interactive.bats but is currently skipped for remote
exec pending additional infrastructure work.

Signed-off-by: shiavm006 <shivammittal42006@gmail.com>

Author: shiavm006

pkg/bindings/containers/attach.go

@@ -402,6 +402,15 @@ func ExecStartAndAttach(ctx context.Context, sessionID string, options *ExecStar
 		isTerm = respStruct.ProcessConfig.Tty
 	}
 
+	// Extract and parse detach keys from the exec session
+	detachKeysInBytes := []byte{}
+	if respStruct.DetachKeys != "" {
+		detachKeysInBytes, err = term.ToBytes(respStruct.DetachKeys)
+		if err != nil {
+			return fmt.Errorf("invalid detach keys in exec session: %w", err)
+		}
+	}
+
 	// If we are in TTY mode, we need to set raw mode for the terminal.
 	// TODO: Share all of this with Attach() for containers.
 	needTTY := terminalFile != nil && terminal.IsTerminal(int(terminalFile.Fd())) && isTerm
@@ -458,7 +467,7 @@ func ExecStartAndAttach(ctx context.Context, sessionID string, options *ExecStar
 	if options.GetAttachInput() {
 		go func() {
 			logrus.Debugf("Copying STDIN to socket")
-			_, err := detach.Copy(socket, options.InputStream, []byte{})
+			_, err := detach.Copy(socket, options.InputStream, detachKeysInBytes)
 			// Ignore "closed network connection" as it occurs when the exec ends, which is expected.
 			// This avoids noisy logs but does not fix the goroutine leak
 			// https://github.com/containers/podman/issues/25344
@@ -479,7 +488,7 @@ func ExecStartAndAttach(ctx context.Context, sessionID string, options *ExecStar
 			return fmt.Errorf("exec session %s has a terminal and must have STDOUT enabled", sessionID)
 		}
 		// If not multiplex'ed, read from server and write to stdout
-		_, err := detach.Copy(options.GetOutputStream(), socket, []byte{})
+		_, err := detach.Copy(options.GetOutputStream(), socket, detachKeysInBytes)
 		if err != nil {
 			return err
 		}