Persist circuit cell edits

AGENTS.md

@@ -220,15 +220,18 @@ After saving, the row becomes linked to the new project device.
 
 ## Undo / Redo
 
-Session-local UI undo/redo exists for structural and destructive operations.
-The server already persists immutable revisions and project-wide undo/redo
-eligibility for the first commands. Public command, undo and redo endpoints
-exist for Circuit and CircuitDeviceRow field updates as well as
-Circuit/CircuitDeviceRow insertion and deletion. Complete command coverage and
-the UI cutover remain future work. CircuitDeviceRow moves between existing
-circuits and moves that create one new placeholder target circuit are also
-persisted. The latter stores the complete empty target snapshot so undo can
-restore the rows and remove only the unchanged generated circuit. Complete
+The editor's visible undo/redo stack remains session-local while structural and
+destructive operations are being migrated. Existing Circuit and
+CircuitDeviceRow cell edits already execute persistent project commands and
+their toolbar undo/redo actions use the project-wide history endpoints. The
+tree response supplies the optimistic `currentRevision`; the obsolete direct
+PATCH routes for these fields are removed. Reloading the page does not yet
+reconstruct the visible editor stack. Public command, undo and redo endpoints
+also exist for Circuit/CircuitDeviceRow insertion and deletion.
+CircuitDeviceRow moves between existing circuits and moves that create one new
+placeholder target circuit are persisted. The latter stores the complete empty
+target snapshot so undo can restore the rows and remove only the unchanged
+generated circuit. Complete
 in-section Circuit reorders are persisted separately and change sort positions
 without changing equipment identifiers. Explicit complete-section renumbering
 is persisted through a separate collision-safe command and is never triggered