M5.3: scope memory

A project's notes have their own folder, memory/nisse-dev/projects/<project>/,
with its own index; remember and forget take scope (general, or project:
always the current item's own, so no item writes another project's notes,
and a conversation has none). At an item's start the transcript gets the
general index and its project's, never another's. Index links are pages
from the vault's root, as SilverBullet names them.

The closing pass's memory_done can name repository documents the item left
out of date; the harness says so in the thread and records it. The prompt:
the repository is the authority, and a note that disagrees is corrected.

With the operator: ARCHITECTURE.md isn't put into every item's context (its
size); the infrastructure world model waits for nisse-ops. The walk writes
project notes and checks they come only from that project's items.

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

docs/Development-Plan.md

@@ -512,7 +512,22 @@ notes are written and read (L6.4).
 - The walk remembers and forgets, and checks that nothing lands outside the
   agent's folder.
 
-**M5.3 Scope memory.** *Pre-approved.* Scope memory outliving work items (L6.3).
+**M5.3 Scope memory.** *Discussed with the operator.* **Done** (this PR) (L6.3).
+- Project notes have their own folder, `memory/nisse-dev/projects/<project>/`,
+  with its own index; `remember` and `forget` take `scope` (`general`, or
+  `project`: always the current item's, so no item writes another project's
+  notes; a conversation has none). At an item's start the transcript gets the
+  general index and its project's, never another project's.
+- Index links are pages from the vault's root, as SilverBullet names them.
+- The closing pass's `memory_done` can name repository documents the item left
+  out of date: said in the thread and recorded, for the operator.
+- The prompt: the repository is the authority; a note disagreeing with it is
+  corrected; don't remember what it already holds.
+- Decided with the operator: `ARCHITECTURE.md` isn't put into every item's
+  context (its size); the driver still reads it as told. The infrastructure
+  world model waits for `nisse-ops` (Phase 7).
+- The walk writes project notes and checks they come only from that project's
+  items.
 
 **M5.4 The operator's view.** *Pre-approved.* SilverBullet in its own container on
 the vault: the operator's folders read-write, the agents' read-only (L10), behind