M5c-1 plan: task 12, memory writes decided for Honcho as they are journalled

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

docs/plans/M5c1/11-memoryd-honcho-worker.md

@@ -106,9 +106,11 @@ Fixture `08-messages-add-batch.json` is the shape: `POST
 
 answered 201 with the messages made, whose `id`s go in the `Sent` record in order. Fixtures 09
 and 10: a message of 25,000 characters is taken, one of 25,001 refused (422). Characters, not
-bytes: `parts` cuts by `char`. The number of messages in one batch Honcho takes is not in the
-recorded responses; `MAX_BATCH` is 100, `roncho`'s limit for a batch of conclusions, and a turn
-that needs more (over 2,500,000 characters) is marked failed without a request.
+bytes: `parts` cuts by `char`. A batch holds 1 to 100 messages, and a message's content may be
+empty: Honcho's `src/schemas/api.py` (main) has `MessageBatchCreate.messages: Field(...,
+min_length=1, max_length=100)` and `MessageCreate.content` with `min_length=0` (the same cap of
+100 holds for a batch of conclusions). So `MAX_BATCH` is 100, and a turn that needs more (over
+2,500,000 characters) is marked failed without a request.
 
 ## The lines the worker logs