hive-matrix-mcp: document redaction power-level + concurrency semantics

hive-matrix-mcp/src/handlers.rs

@@ -423,7 +423,11 @@ pub async fn send_redact(
     };
     // Redaction is irreversible: the homeserver drops the event content and
     // keeps only the shell + reason. A fresh txn id (None) is fine — this is
-    // a one-shot operator/agent action, not a retried send.
+    // a one-shot operator/agent action, not a retried send. Power level is
+    // enforced server-side (own events always; others' need a moderator PL),
+    // so a redact that races a concurrent edit is resolved by the server.
+    // NOTE(droggelbecher): no client-side pre-check — we let the server be
+    // the authority on both permission and ordering.
     match room.redact(&eid, reason, None).await {
         Ok(resp) => DaemonResponse::ok(&serde_json::json!({
             "event_id": resp.event_id.to_string(),