Counter

examples/counter/programs/counter.py stores authority, count, and bump. initialize creates the PDA (seed counter) and sets the count to 0. increment requires counter.authority == authority.key and then adds by with checked arithmetic.

Unauthorized is error code 6000. Overflow returns 1009 and does not change the account. The source positions in the program log are (counter.py:51) for the authority check and (counter.py:52) for the add.