fix: exemplar draw keeps other classes' full-set preview (REQ-182 amended)

- AutoAnnotateModal: render merges last full-set detections for
  non-exemplared classes with conditioned results for exemplared ones
  (selected-not-exemplared filter); drawing an example no longer clears
  the other classes' detections
- Run Preview now always refreshes full-set first (exemplars: []) then
  re-runs exemplared classes
- docs: REQ-182 amended (merge semantics), design/ui-spec/tasks synced

docs/tasks.md

@@ -1272,10 +1272,11 @@ failure modes to the counting path. The saving was always on the browser side.
 
 1. Exemplar pools keyed by class and a per-class accumulating preview in the auto-annotate
    modal — switching the active class swaps pools and a frame change clears them all
-   (REQ-172); a redraw re-runs only the touched class against its own pool, the canvas unions
-   every exemplared class, classes without examples contribute nothing while any example
-   exists, clearing the last example falls back to the full-set preview, no examples at all →
-   the unchanged full-set request (REQ-182) → verify: **[DONE]** `cd frontend && npm run
+   (REQ-172); a redraw re-runs only the touched class against its own pool, the canvas merges
+   exemplared classes' conditioned results over the last full-set detections of the other
+   selected classes (REQ-182, as amended — superseded by the merged-preview entry below),
+   clearing the last example returns that class to its full-set detections, no examples at
+   all → the unchanged full-set request (REQ-182) → verify: **[DONE]** `cd frontend && npm run
    build` passes (✓ 536 ms, 69 modules); `wc -l` caps hold —
    `frontend/src/components/AutoAnnotateModal.jsx` (400) and
    `frontend/src/hooks/useExemplarPools.js` (100) both ≤ 400; rebuilt Docker frontend
@@ -1348,6 +1349,18 @@ read it.
    invalid→global, float-noise case 0.30000000000000004 → `0.3`); browser clipboard
    click-test NOT automated — manual click-test pending.
 
+## Task — Merged preview: exemplar draw keeps other classes (REQ-182 amended) `[DONE]`
+
+1. Non-exemplared classes keep last full-set detections when an exemplar is drawn;
+   exemplared class shows conditioned results replacing its own; Run Preview
+   refreshes full-set first (exemplars: []) then exemplared; draw never full-set
+   re-runs → verify: **[DONE]** `cd frontend && npm run build` passes (✓ 523 ms);
+   `wc -l frontend/src/components/AutoAnnotateModal.jsx` = 400 (at cap; blank lines
+   trimmed to fit, adjudicated by review); `git diff --stat` = 1 code file; grep
+   proof full-set call has `exemplars: []` (`AutoAnnotateModal.jsx:118`); 7-case
+   walkthrough in t11-report.md; browser test (draw example after Run Preview, other
+   classes persist) NOT automated — manual click-test pending.
+
 ## Known open points
 
 - *Not closed by any task, by choice:* **any rebuild kills the running job.** Task 14's resume