M5.2: agent memory

remember(name, description, fact) and forget(name, why): control tools for
the driver (before the go-ahead too) and conversations, writing only the
agent's own vault folder, one note per fact with its provenance. No one
agrees first; each change is a line in the thread. The harness keeps the
index and puts it into the transcript once per item, with a hash.

At an item's close, completed or abandoned, a bounded memory pass (the
driver's model, its own transcript and view) records what was decided and
learned; it never holds the close up (tuning.memory.max_turns).

With the operator: corrections may be paraphrased (L6 changed), the model
forgets on its own, and nothing limits what may prompt a note. The walk
remembers and forgets, and checks nothing lands outside the agent's folder.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01J5Utyfzw7gF7UhjRDEtjTk

docs/Architecture.md

@@ -346,17 +346,21 @@ work-item start, with the repository as the authority; for infrastructure, the
 world model in the vault (L10).
 
 **4. Agent memory:** the agent's own notes (the operator's preferences, lessons,
-recurring decisions and their reasons), one note per fact with an index, in its
-folder under `memory/` in the vault (L10). Read at work-item start and before
-decisions the notes cover. Visible to the operator, who corrects it through
-conversation.
+recurring decisions and their reasons), one note per fact with an index the
+harness keeps, in its folder under `memory/` in the vault (L10). The model
+writes, updates and forgets them itself, without asking; each change is said in
+the thread. The index is put into the transcript at a work item's start; a note
+is read before decisions it covers. Visible to the operator, who corrects it
+through conversation, not by editing it.
 
 **5. Never memory:** Matrix history, provider-side session state, build artifacts,
 a previous task's workspace.
 
-**Writing memory:** at work-item close (what was done and decided, into scope memory
-or agent memory as it belongs); when a fact is learned, with its source and time;
-operator corrections verbatim, with attribution, never paraphrased.
+**Writing memory:** when a fact is learned, with its source and time; at work-item
+close, by a bounded pass of its own (what was decided and learned, into scope memory
+or agent memory as it belongs), so it never depends on the model thinking of it;
+operator corrections faithfully, with attribution. Paraphrase is fine: after a
+back-and-forth, the gist is what matters.
 
 **Using memory:** everything read is snapshotted into the transcript with its
 provenance (source, revision or content hash, time), once per item. **Memory is a