docs(cli-reference): regenerate for new received flags

received gained --limit, --since, --clear --before in the CLI overhaul.
The cli-reference-check gate caught the stale summary line.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: teovl

docs/cli-reference.md

@@ -61,7 +61,7 @@ Management commands:
   pilotctl disconnect <conn_id>
 
 Mailbox:
-  pilotctl received [--clear]
+  pilotctl received [--limit <n>] [--since <dur>] [--clear [--before <dur>]]
   pilotctl inbox [--clear]
 
 Service Agents: