🐛 TUI should strive to prevent zombie key deletion #41
Description
Currently TUI allows deletion of a key that is not active but still used for voting.
When a key expires, there is no lag—the total online stake is already adjusted ahead of time to account for that, and the key stops voting exactly after (or on) the expiry round.
When a new replacement key is online there is a 320 round lag where old key material is still needed.
The node marks the old key as "not active", but it is actually in a zombie state - still voting for 320 rounds.
It is not possible (statelessly or without an indexer) to get the actual round where the old one is no longer needed.
Suggest TUI adopts either of:
- no key deletion unless it is expired (should delete itself)
- prevent deletion of matching key at least until 320 + human lag rounds away from the first valid of the current key
- making gruesome warnings about key deletion that might be still voting