Make conversation queues mutually exclusive

docs/product-and-safety.md

@@ -54,7 +54,7 @@ The snapshot matters: changing configuration later must not silently rewrite the
 
 Within those boundaries, R4R replies are expected to participate naturally in consensual adult NSFW conversation instead of moralizing, declining the topic, or diverting ordinary flirting into generic small talk. In-character soft refusals are treated like provider refusals and fall through to the next configured chat model. This does not weaken recipient boundaries, the under-18 handoff, seller/off-platform controls, location and meeting prohibitions, or the separate media-request rules.
 
-Two of those stops are terminal rather than handoffs. A reply that pushes the conversation onto another messaging app, asks for contact details, solicits payment, points at a paid-content funnel, or runs the age/bot "verification" scam sets the automation status to `killed`, marks the durable seller flag, and resolves the operator's triage state, so the conversation leaves every actionable queue instead of collecting in the manual one. Detection normalizes the text first — unicode folding, zero-width stripping, leet mapping, separator removal — because these words are routinely obfuscated (`0nlyfans`, `t3l3gram`, `t e l e g r a m`). Ambiguous terms need context: `snap` on its own is a photo request in this product and never a kill on its own. Off-platform kills are a safety control and stay on independently of `reddit.filterSellers`; a configured seller keyword or domain also kills unless `conversations.killOnSellerKeyword` is disabled. Under-18 disclosures and in-person/contact-detail asks remain human handoffs, and now apply to every policy mode rather than the R4R ones only.
+Two of those stops are terminal rather than handoffs. A reply that pushes the conversation onto another messaging app, asks for contact details, solicits payment, points at a paid-content funnel, or runs the age/bot "verification" scam sets the automation status to `killed`, marks the durable seller flag, and resolves the operator's triage state, so the conversation leaves every actionable queue instead of collecting in the manual one. The same deterministic decision runs against cached inbound history during each running-mode reply scan and during the operator-forced seller scan, including conversations that are too old to revive for an automated reply or have already become operator-owned. Detection normalizes the text first — unicode folding, zero-width stripping, leet mapping, separator removal — because these words are routinely obfuscated (`0nlyfans`, `t3l3gram`, `t e l e g r a m`). Ambiguous terms need context: `snap` on its own is a photo request in this product and never a kill on its own. Off-platform kills are a safety control and stay on independently of `reddit.filterSellers`; a configured seller keyword or domain also kills unless `conversations.killOnSellerKeyword` is disabled. Under-18 disclosures and in-person/contact-detail asks remain human handoffs, and now apply to every policy mode rather than the R4R ones only.
 
 Optional second-stage AI screening (`conversations.aiReplyScreening`) runs only when the deterministic rules come up clean, classifies the inbound side of the conversation as genuine, seller, off-platform, scam, bot, or unclear, and kills at or above `killConfidence` while handing off at or above `flagConfidence`. It fails open: a classifier error or outage never blocks a reply, and each inbound event is screened at most once per process. Short refusals are interpreted in sequence: phrases such as “I’m good” become media boundaries only when they answer a media request.