Keymanager API (Phase 1)
- List, import, and delete local validator keystores from the TUI
- Enable Keymanager HTTP API for Lighthouse, Nimbus, Lodestar, and Prysm
- Prysm: wallet bootstrap, RPC/REST flags, empty-wallet handling, offer to start a stopped validator
Fixes
- View logs: Ctrl-C returns to the EthPillar submenu instead of exiting the process