IMO, the clay bank on the right side of your photo is NOT stable, and will erode into your pond.
Do you get lots of rainfall? Do you get freeze/thaw cycles? (Freeze/thaw cycles on exposed moist clay can turn it into loose powder.)
I would follow the good advice above about burying your liner edges.
As to the clay bank, you have several possible solutions. Since you are trying to make an attractive pond feature pick one that covers the required "engineering", yet still is pleasing to your eye.
One solution is some large, blockish rocks right up against the clay bank.
Another is to cut the bank a bit to a slope less steep than vertical. You can then put down some good landscape fabric and bury the top edge. (You want water flows to go over, rather than under the fabric.) You could then finish the slope with some cobble size rocks similar to your edge rocks.
You could also cut back the slope and plant some very dense groundcover plants that flourish in your area and are adapted to clay soil.
Finally, no matter how you finish that bank, you might add a water diversion system to keep runoff away from that bank and your pond. You could build a shallow berm (inches high) in your garden, or even install a french drain. You can then use your garden landscaping to hide that if needed for your final "look".
Have fun with your new mini-pond!
