Rewrite project documentation

docs/circuit-list-editor-architecture.md

@@ -40,9 +40,10 @@ The pure grid modules have no React state and are covered by focused unit tests.
 - `ProjectDevice`
   - Reusable device template entity at project level.
   - Can be linked to `CircuitDeviceRow` entries, with copied display values on insert.
-- Legacy `Consumer`
-  - Old row-first model still present for compatibility/migration.
-  - Should not be extended for new circuit-list behavior.
+- Retained legacy migration source
+  - Old `consumers` rows, mappings and reports are available only to explicit
+    database upgrade tooling.
+  - They are not application-domain entities and have no UI or API.
 
 ## Why A Circuit Is Not One Row
 
@@ -104,10 +105,14 @@ Primary circuit-first editor route:
 
 - `/projects/:projectId/circuit-lists/:circuitListId/tree-edit`
 
-Legacy route remains separate (read-only/preview/migration transition path) and is intentionally not merged into the editable tree editor.
+The sibling `/tree` route is a read-only structure preview. Old
+`/projects/:projectId/circuit-lists` bookmarks redirect to the project page.
 
 ## Future Persistence Direction
 
 Persistent undo/redo, project revisions, logical snapshots, external-model exchange and PostgreSQL readiness are specified in [Project History and External Model Architecture](./project-history-and-external-model-architecture.md).
 
-Near-term refactoring must move command and transaction ownership toward server-side, project-scoped change sets. Database backups remain separate from user-visible project snapshots.
+Critical multi-write commands already use explicit persistence transaction
+adapters. The next step is to compose these command boundaries into server-side,
+project-scoped revisions and change sets. Database backups remain separate from
+user-visible project snapshots.