docs(bluebubbles): document replyContextApiFallback config knob

docs/channels/bluebubbles.md

@@ -581,6 +581,7 @@ Full configuration: [Configuration](/gateway/configuration)
     - `channels.bluebubbles.coalesceSameSenderDms`: Merge consecutive same-sender DM webhooks into one agent turn so Apple's text+URL split-send arrives as a single message (default: `false`). See [Coalescing split-send DMs](#coalescing-split-send-dms-command--url-in-one-composition) for scenarios, window tuning, and trade-offs. Widens the default inbound debounce window from 500 ms to 2500 ms when enabled without an explicit `messages.inbound.byChannel.bluebubbles`.
     - `channels.bluebubbles.historyLimit`: Max group messages for context (0 disables).
     - `channels.bluebubbles.dmHistoryLimit`: DM history limit.
+    - `channels.bluebubbles.replyContextApiFallback`: When an inbound reply lands without `replyToBody`/`replyToSender` and the in-memory reply-context cache misses, fetch the original message from the BlueBubbles HTTP API as a best-effort fallback (default: `false`). Useful for multi-instance deployments sharing one BlueBubbles account, after process restarts, or after long-lived TTL/LRU cache eviction. The fetch is SSRF-guarded by the same policy as every other BlueBubbles client request, never throws, and populates the cache so subsequent replies amortize. Per-account override: `channels.bluebubbles.accounts.<accountId>.replyContextApiFallback`. A channel-level setting propagates to accounts that omit the flag.
 
   </Accordion>
   <Accordion title="Actions and accounts">