Merge remote-tracking branch 'origin/master' into feat/todo-multi-in-progress

# Conflicts:
#	.agents/notes/implemented/feature/2026-06-29-todo-write-tool.i18n.yaml
#	.agents/notes/implemented/feature/2026-07-23-web-todo-display.i18n.yaml
#	docs/core-data-structures/session.i18n.yaml
#	examples/acp-agent/tests/snapshots/fs-policy-reject/session.jsonl
#	examples/acp-agent/tests/snapshots/fs-write-overwrite/session.jsonl
#	examples/acp-agent/tests/snapshots/fs-write/session.jsonl
#	examples/acp-agent/tests/snapshots/todo-write/session.jsonl
#	examples/headless-agent/tests/todo-write.e2e.ts
#	packages/client/ui-conversation/README.i18n.yaml
#	packages/client/ui-conversation/README.md
#	packages/client/ui-conversation/README.zh.md
#	packages/todo/tool-todo/README.i18n.yaml

packages/todo/tool-todo/src/index.ts

@@ -75,17 +75,23 @@ const todosProjectionSchema: ZodType<TodoItem[] | null> = z.union([
 /** Register the `todo_write` tool on `ctx.tools` and, when the session-projection seam is composed, the `todos` unit. */
 export function apply(ctx: Context): void {
   // The unit child activates only when a projection registry is composed
-  // (headless assemblies without the seam stay unaffected). Pure last-wins
-  // fold: state is the latest whole todo/write list, null before the first
-  // write; every other event returns the same reference (no downstream work).
+  // (headless assemblies without the seam stay unaffected). Standing-plan fold:
+  // latest whole todo/write list, cleared by the next turn/start (turn/end keeps
+  // the finished checklist visible); null before the first write or after a
+  // later turn begins; every other event returns the same state reference.
   ctx.inject(['sessionProjections'], (projectionCtx) => {
     projectionCtx.sessionProjections.register<'todos', TodoItem[] | null>({
       key: 'todos',
       schema: todosProjectionSchema,
       init: () => null,
-      apply: (state, event) => (event.type === 'todo/write' ? event.data.todos : state),
+      apply: (state, event) => {
+        if (event.type === 'todo/write') return event.data.todos
+        if (event.type === 'turn/start') return null
+        return state
+      },
       view: state => state,
-      stateVersion: 1,
+      // Fold semantics changed: turn/start clears the standing plan (was last-write-wins only).
+      stateVersion: 2,
     })
   })
   ctx.tools.register(defineTool({