Companion to the Verify silent-drop fix. AddBlock's only rejection is 'block already
exists', which a self-built block hits whenever the VM re-mints an identical envelope
(proposervm truncates the block timestamp to a whole second, so rebuilds within that
second share a blkID). The bare continue skipped Propose/RequestVotes, so the block
never reached peers and never got decided, while the VM re-notified on still-pending
txs — a silent rebuild storm with the chain pinned at its height and nothing logged.
zeekay
7c620cff43