dnd 3.5e – When do you lose bonus power points?

I’m looking specifically at the feat Azure Talent, from Magic of Incarnum. I’ve read various debates about whether or not one can combine it with things like Psycarnum Infusion to get infinite power points, but right now I’m interested in Azure Talent alone.

The relevant text is this:

Once per day, you can invest essentia into this feat. You gain bonus power points equal to twice the
invested essentia. Once the amount of essentia invested is chosen, it cannot be altered and remains invested for 24 hours.

So, say I have 1 point of essentia. I invest it into Azure Talent, and get 2 bonus power points. Do those power points go away at the end of the day? They’re bonus power points, not temporary power points, and as far as I can tell there’s nothing that automatically recalculates your power points each day. As long as I’m not spending these power points, can I just keep accumulating them, 2 per day?

On a similar note, if I cast fox’s cunning (assuming I calculate PP off of intelligence) before concentrating to regain power points (as described on page 64 of the Expanded Psionics Handbook), do I get extra PP even after the fox’s cunning wears off? If I have a bunch of low-level psion followers or another manifester PC, can they just keep manifesting bestow power on me every day well past my normal daily PP reserve?

My current understanding is that bonus power points only get calculated when a manifester deliberately concentrates to regain daily power points, and even then they can only go up, but this has some weird implications, like psions spending their downtime stockpiling extra power points, that makes me think I’ve missed something. Is there a cap on power points, somewhere?