perf(todos): preserve summary identity with linear deduplication

loopx/control_plane/todos/context_projection.ts

@@ -259,6 +259,8 @@ export function projectTodoSummaryDisplay(input: JsonObject, onSource?: (key: st
     return gate.gate_state === "cleared_with_successor" && Array.isArray(gate.successor_todo_ids) ? gate.successor_todo_ids.map(id).filter(Boolean) : [];
   }));
   const selected: {item: JsonObject; text: unknown}[] = [], seen = new Set<string>();
+  const rawIds = new Set<unknown>();
+  const coordinates = new Map<unknown, {all: Set<string>; anonymous?: Set<string>}>();
   if (source) {
     for (const key of planning ? PLANNING_SOURCES : SUMMARY_SOURCES) {
       for (const [index, value] of (Array.isArray(source[key]) ? source[key] as unknown[] : []).entries()) {
@@ -267,7 +269,20 @@ export function projectTodoSummaryDisplay(input: JsonObject, onSource?: (key: st
         let todo = id(item.todo_id);
         if (terminal && !todo) {const legacy = stripPythonWhitespace(pythonFieldText(item, "todo_id")); if (legacy.startsWith("todo_")) todo = legacy;}
         if (!body || (planning ? !todo || !terminal && item.status === "done" || seen.has(todo!) : item.done === true)) continue;
-        if (!planning && selected.some(({item: prior, text}) => item.todo_id && prior.todo_id ? item.todo_id === prior.todo_id : prior.index === item.index && text === body)) continue;
+        if (!planning) {
+          // Either missing ID makes legacy coordinates decisive. Preserve raw
+          // IDs and strict equality: unlike Map keys, NaN never equals itself.
+          const rawId = item.todo_id, coordinate = item.index;
+          const prior = coordinate === coordinate ? coordinates.get(coordinate) : undefined;
+          if (rawId ? rawIds.has(rawId) || prior?.anonymous?.has(body) : prior?.all.has(body)) continue;
+          if (rawId) rawIds.add(rawId);
+          if (coordinate === coordinate) {
+            const entry = prior ?? {all: new Set<string>(), anonymous: undefined};
+            entry.all.add(body);
+            if (!rawId) (entry.anonymous ??= new Set<string>()).add(body);
+            coordinates.set(coordinate, entry);
+          }
+        }
         if (todo) seen.add(todo);
         selected.push({item, text: body});
         onSource?.(key, index);

tests/control_plane_ts/content_digest_single_owner.test.ts

@@ -186,6 +186,7 @@ const CANONICAL_CONSUMERS = [
   "control_plane/work_items/task_lease_lifecycle.ts",
   "control_plane/work_items/task_lease_lifecycle_request.ts",
   "control_plane/work_items/task_lease_workspace.ts",
+  "control_plane/work_items/yardstick_decision.ts",
   "zcode_goal_mode/cli.ts",
   "zcode_goal_mode/runtime.ts",
 ];

tests/control_plane_ts/todo_summary_lanes.test.ts

@@ -97,7 +97,7 @@ test("conflicting display fragments cannot certify a complete source", () => {
   assert.equal(result.complete, false);
 });
 
-import {projectTodoSummaryDisplay} from "../../loopx/control_plane/todos/context_projection.ts";
+import {projectTodoContextPage, projectTodoSummaryDisplay} from "../../loopx/control_plane/todos/context_projection.ts";
 
 test("display source lanes preserve first identity, legacy coordinates and explicit readiness", () => {
   const record = {active_next_action_items: [{todo_id: "todo_first", text: " First ", status: "open", resume_when: "todo_done:todo_gate"}],
@@ -132,3 +132,48 @@ test("planning keeps distinct domain states and terminal frontier evidence, with
   assert.deepEqual(terminal[0]!.depends_on_todo_ids, ["todo_dependency"]);
   assert.equal(terminal[1]!.note, "Evidence tail");
 });
+
+test("summary source identity keeps raw IDs and strict legacy coordinates", () => {
+  const cases: {name: string; items: JsonObject[]; selected: number[]}[] = [
+    {name: "raw identities and anonymous collisions", items: [
+      {todo_id: "todo_same", index: 1, text: " First "},
+      {todo_id: "todo_same", index: 2, text: "Duplicate id"},
+      {todo_id: " todo_same ", index: 1, text: "Second spelling"},
+      {todo_id: "todo_a", index: 7, text: " Same "},
+      {todo_id: "todo_b", index: 7, text: "Same"},
+      {index: 7, text: "Same"}, {index: 8, text: " Legacy "},
+      {todo_id: "todo_c", index: 8, text: "Legacy"},
+      {index: 9, text: "Legacy"}], selected: [0, 2, 3, 4, 6, 8]},
+    {name: "strict coordinates", items: [
+      {index: 2, text: "Coordinate"}, {index: "2", text: "Coordinate"},
+      {text: "Missing"}, {index: null, text: "Missing"},
+      {index: NaN, text: "Nonfinite"}, {index: NaN, text: "Nonfinite"},
+      {index: 0, text: "Zero"}, {index: -0, text: "Zero"},
+      {index: 2, text: "Coordinate"}], selected: [0, 1, 2, 3, 4, 5, 6]},
+    {name: "truthy and falsy raw identities", items: [
+      {todo_id: 1, index: 1, text: "Number id"},
+      {todo_id: true, index: 2, text: "Boolean id"},
+      {todo_id: 1, index: 3, text: "Same number id"},
+      {todo_id: 0, index: 4, text: "Zero id"},
+      {todo_id: 0, index: 5, text: "Zero id"},
+      {todo_id: "todo_falsy", index: 6, text: "False id collision"},
+      {todo_id: false, index: 6, text: "False id collision"},
+      {todo_id: "", index: 7, text: "Empty id"},
+      {todo_id: null, index: 7, text: "Empty id"}], selected: [0, 1, 3, 4, 5, 7]},
+  ];
+  for (const {name, items, selected} of cases) {
+    const before = structuredClone(items), visited: number[] = [];
+    const source = {record: {items}};
+    const rows = projectTodoSummaryDisplay({source}, (_key, index) => visited.push(index));
+    assert.deepEqual(visited, selected, name);
+    assert.equal(rows.length, selected.length, name);
+    assert.deepEqual(projectTodoContextPage({summary_display: {source}}).items, rows, name);
+    assert.deepEqual(items, before, name);
+  }
+});
+
+test("flat summary items keep duplicate rows without source selection", () => {
+  const record = {todo_id: "todo_same", text: "Same row"};
+  const result = projectTodoContextPage({summary_display: {items: [{record}, {record}]}});
+  assert.equal((result.items as JsonObject[]).length, 2);
+});