Fixed-index truncation could split an HTML tag or entity or drop a closing tag, making Telegram reject the whole message with 'can't parse entities'. Cut on a newline boundary where tags are balanced, reserve room for a truncation notice, and strip any trailing partial markup.
Replace the per-subscriber SISMEMBER delivery check with a single
SMEMBERS per event plus in-memory lookups, cutting N round-trips to one.
Remove the component-label helpers duplicated between poller and bot by
exporting the canonical versions from poller; bot already depends on it.
Collapse the repeated component checkpoint closures into a shared helper.
Drop the redundant escapeAttr alias and the unused variadic on bot.New.
tiennm99