Add NdbCompactionProgress and Step with user-facing titles/details,
and a progress callback to Ndb.compact_if_needed to emit stage updates.
Refactor CompactionView to a single CompactionState and render linear
progress, step title/detail and percentage. Ensure UI updates happen on
the MainActor and surface errors/completion cleanly.
Changelog-None
Closes: https://github.com/damus-io/damus/issues/3730
Signed-off-by: Daniel D’Aquino <daniel@daquino.me>
Daniel D’Aquino
d6654dff29