It is clear you cannot do anything to have a client leave them.
It says you cannot assist a client. So if they call you and you then have them come to your new job that would fall under the definition of assist.
Any actions that result them losing work by you or third parties referring them to you is a breach.
I am surprised that you agreed to 12 months In your industry 3 - 6 months is the usual because there are many that do the job and there is competition.
If you are contacted and they come to you, then you have to wait and see what the employer does. If they send you a letter saying you are in breach then prepare for a court case if you dont stop.
I have just completed a case where it cost my client $30,000.00 to fight it and we settled. It took 9 months of going back and forth to court drafting Affidavits and arguments.
In my opinion you face the possibility of a court action even if they contact you.
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