Prevent opening hand result changes before duel start

[purerosefallen]

Summary

• Reject 0 as an invalid opening hand result.
• Ignore repeated opening hand result packets once a side has already submitted.
• Use the tag duel team bit to resolve which side's hand result is being submitted.

Notes

This keeps the opening rock-paper-scissors result stable after the first valid submission, while still allowing a new submission round after a draw resets the stored results.

Not changing here