chore: Limit expiry value to 32 bits.

[romange]

We use adaptive precision, where we keep "millis" precision if we can, and switch to seconds precision if the deadline is too large.

This actually was before but now I reduced the cut-off to 4B ms, or 49 days. Also, the ttl in seconds is now limited to 4B sec, with larger values quietly rounded down to this limit.

[romange]

the next step would be to start using expire_base_ and generations to represent the absolute times using ~49 days ExpirePeriod. The absolute time := expire_base_ + expire_period so we should refresh expire_base_ daily to maintain 48-49 days span.

[dranikpg]

Not sure if I have to start using the phrase "not sure" less 🤔