Restore loads a checkpoint from the store, resolves the agent from
a registry, and re-enters coreLoop. Handles suspended, nested
suspended (concurrent inner restore), and awaiting-approval states.
Partial progress is saved when some inner agents complete while
others remain suspended.
Signed-off-by: Aurélien Sibiril <81782+aureliensibiril@users.noreply.github.com>