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/design.md

@@ -346,12 +346,15 @@ switching the active class swaps pools instead of discarding them (REQ-172). The
 per class and accumulates (REQ-182): exemplar changes share **one 250 ms debounce** that
 re-runs the most recently touched class against its own pool and replaces only that class's
 shapes — rapid alternation between classes re-runs only the last one — while the other
-exemplared classes' results stay on screen and the canvas renders the union of every class
-with a non-empty pool. Undo is the same re-run with the shortened pool, because SAM3 can
-only append geometric prompts. Clearing the last example sends no request and restores the
-plain full-set preview (the session's last full-set run, blank if none ran yet);
-Run Preview with examples runs the exemplared classes
-sequentially and merges, without examples it is the unchanged full-set request. The
+exemplared classes' results stay on screen and the canvas **merges** (amended REQ-182):
+exemplared classes contribute their pool-conditioned results (replacing their own full-set
+boxes), every other selected class keeps the detections of the last full-set run on that
+frame. Undo is the same re-run with the shortened pool, because SAM3 can
+only append geometric prompts. Clearing a class's last example sends no request and returns
+that class to its full-set detections (blank if no full-set run covered it); clearing all
+examples is then a plain full-set view again. Run Preview always refreshes the full-set for
+every selected class first (with empty exemplars), then re-runs the exemplared classes
+sequentially; drawing an example never triggers a full-set re-run. The
 per-class overrides table also carries a **Container** checkbox (REQ-184) that toggles
 `project_classes.container` through `PATCH /api/projects/{id} { containers: … }`. The same
 table carries a **Copy** button (REQ-186): one click puts every selected class's effective

docs/requirements.md

@@ -129,12 +129,14 @@ changes.
   pool on the current frame: switching the active class shows that class's pool instead of
   discarding the others, and a new frame discards them all.
 - **REQ-182** — The auto-annotate preview is **per class and accumulates**. While at least one
-  class has example boxes on the previewed frame, the preview shows only the classes that have
-  examples, each conditioned on its own pool; re-drawing one class's example refreshes only
-  that class's predictions and leaves the other exemplared classes' results on screen. Classes
-  without examples contribute nothing while any example exists, and clearing the last example
-  restores the plain full-set preview. The preview and the batch job still use the same
-  thresholds and per-class overrides.
+  class has example boxes on the previewed frame, the preview **merges**: classes with examples
+  show only their pool-conditioned results, replacing their own full-set boxes, while classes
+  without examples keep the detections of the last full-set run on that frame. Re-drawing one
+  class's example refreshes only that class's predictions and leaves everything else on screen.
+  Run Preview always refreshes the full-set for every selected class first, then the exemplared
+  ones; drawing an example never triggers a full-set re-run. Clearing a class's last example
+  returns that class to its full-set detections, so clearing them all is a plain full-set view
+  again. The preview and the batch job still use the same thresholds and per-class overrides.
 - **REQ-186** — The auto-annotate parameters table has a **copy button** that puts every
   selected class's effective settings on the clipboard as short text, one class per line:
   `class <name> conf <v> iou <v> minbox <v> container <true|false>`. Effective means the

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

docs/ui-spec.md

@@ -485,11 +485,14 @@ them all. Adding, undoing or clearing an exemplar records the touched class and
 single revision counter — **one shared debounce** across all classes, 250 ms — which re-runs
 the most recently touched class against its own pool and replaces only its shapes, so rapid
 alternation between classes re-runs only the last one; the other exemplared classes' results
-stay on screen and the canvas shows the union of every class with examples. Classes without
-examples contribute nothing while any example exists; Run Preview with examples runs those
-classes sequentially and merges, and with none it is the plain full-set preview. Clearing the
-last example sends no request and restores the plain full-set preview (the session's last
-full-set run, blank if none ran yet). Drawing a box *is* the question and the redrawn
+stay on screen and the canvas **merges** (amended REQ-182): exemplared classes contribute
+their pool-conditioned results (replacing their own full-set boxes), every other selected
+class keeps the detections of the last full-set run on that frame. Classes without examples
+keep those detections on screen; Run Preview always refreshes the full-set first (empty
+exemplars), then re-runs the exemplared classes sequentially — drawing an example never
+triggers a full-set re-run. Clearing a class's last example sends no request and returns
+that class to its full-set detections (blank if no full-set run covered it); clearing them
+all is a plain full-set view again. Drawing a box *is* the question and the redrawn
 preview is the answer, so no button press sits between them. Re-running is cheap because
 `set_image` is already cached for this frame — only the grounding head runs.
 

frontend/src/components/AutoAnnotateModal.jsx

@@ -20,7 +20,6 @@ export default function AutoAnnotateModal({
   const [minBoxFrac, setMinBoxFrac] = useState(0.0)
   const [classParams, setClassParams] = useState({})
 
-  
   // Class selection state
   const [selectedClasses, setSelectedClasses] = useState(() => {
     if (engine === 'base_model') {
@@ -85,20 +84,25 @@ export default function AutoAnnotateModal({
   })
 
   const activePool = activeClassName ? pools[activeClassName] || [] : []
-  // While any selected class has examples, only those classes contribute.
   const exemplaredClasses = selectedClasses.filter(name => pools[name]?.length)
+  // merged: exemplared classes show conditioned results (replacing their full-set
+  // boxes); everyone else keeps the last full-set run (amended REQ-182)
+  const nameById = Object.fromEntries(project.classes.map(c => [c.class_id, c.name]))
+  const exemplaredSet = new Set(exemplaredClasses)
+  const selectedSet = new Set(selectedClasses)
   const renderShapes = exemplaredClasses.length > 0
-    ? exemplaredClasses.flatMap(name => shapesByClass[name] || [])
+    ? [
+        ...previewShapes.filter(s => {
+          const n = nameById[s.class_id]
+          return selectedSet.has(n) && !exemplaredSet.has(n)
+        }),
+        ...exemplaredClasses.flatMap(name => shapesByClass[name] || []),
+      ]
     : previewShapes
 
   const handlePreview = () => {
-    if (exemplaredClasses.length > 0) {
-      run(exemplaredClasses)
-      return
-    }
     const frame = currentFrame
     if (!frame) return
-
     let isMounted = true
     setIsLoadingPreview(true)
     setPreviewError('')
@@ -111,8 +115,8 @@ export default function AutoAnnotateModal({
       target_class_names: selectedClasses,
       class_params: buildClassParams(classParams),
       custom_model_path: customModelStagedPath,
-      exemplars: engine === 'sam3' ? activePool : [],
-      exemplar_class_name: engine === 'sam3' ? activeClassName : null
+      exemplars: [],
+      exemplar_class_name: null
     }).then(res => {
       if (isMounted && res.shapes) {
         setPreviewShapes(res.shapes)
@@ -123,7 +127,9 @@ export default function AutoAnnotateModal({
       setPreviewError(err.message || 'Preview failed')
       setPreviewShapes([])
     }).finally(() => {
-      setIsLoadingPreview(false)
+      if (!isMounted) return
+      if (exemplaredClasses.length > 0) run(exemplaredClasses)  // manages busy itself
+      else setIsLoadingPreview(false)
     })
   }
 
@@ -212,11 +218,9 @@ export default function AutoAnnotateModal({
         border: '1px solid rgba(168, 85, 247, 0.4)', background: '#18181b',
         overflowY: 'auto', borderRadius: 8
       }}>
-        
         {/* Left Side: Preview */}
         <div style={{ flex: '1 1 450px', display: 'flex', flexDirection: 'column', minWidth: 280 }}>
           <h3 style={{ margin: '0 0 8px 0', color: '#e4e4e7', fontSize: '1rem' }}>Preview</h3>
-          
           <div style={{ position: 'relative', width: '100%', background: '#000', borderRadius: 6, overflow: 'hidden', display: 'flex', justifyContent: 'center', alignItems: 'center' }}>
             {currentFrame ? (
               /* This wrapper must hug the image and nothing else: both overlays
@@ -294,7 +298,6 @@ export default function AutoAnnotateModal({
               </>
             )}
           </div>
-          
           <div style={{ marginTop: 10 }}>
             <div className="row" style={{ justifyContent: 'space-between', marginBottom: 4 }}>
               <span className="hint" style={{ fontSize: '0.8rem' }}>Preview Frame ({frameIndex + 1} / {frames.length}):</span>
@@ -380,7 +383,6 @@ export default function AutoAnnotateModal({
             promptError={promptError}
             savedPrompt={activeClass ? classPrompts[activeClass.class_id] : ''}
           />
-
           <div className="row" style={{ justifyContent: 'flex-end', gap: 10, marginTop: 16, paddingTop: 10, borderTop: '1px solid rgba(255,255,255,0.08)' }}>
             <button className="btn btn-ghost" onClick={onClose} disabled={isSubmitting}>Cancel</button>
             <button
@@ -392,9 +394,7 @@ export default function AutoAnnotateModal({
             </button>
           </div>
         </div>
-
       </div>
     </div>
   )
 }
-