feat(agent): dedupe near-duplicate crops before the SigLIP embed

Figure boxes are already NMS-merged (iou 0.6) and each YOLO detector self-NMSes,
but the combined per-frame crop pile (figure→concept ∪ anatomy component→concept
∪ panel) was embedded with no cross-proposer dedup — so genuine near-duplicates
slipped through (a figure box ≈ an anatomy component on a solo bust; overlapping
booru head classes on one head), embedding the same region twice and burning a
slot against max_regions.

Add detectors.dedupe_crops(): a greedy, high-IoU (default 0.85), kind-aware pass
over the pending (crop, template) list right before embed_batch — drop boxes that
overlap ≥ iou within the same kind, keep the highest score. The high threshold is
deliberate: it collapses only true near-identical boxes while preserving
intentional nested crops across scopes (a whole figure vs a small head component
sit well below it) and distinct kinds (concept vs panel). Env-tunable DEDUPE_IOU
(≥1.0 disables). Runs on CPU before the GPU work, so it cuts both embed cost and
region count. Temporal (cross-frame) dedup deferred. Build marker 2026-07-01.2.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Ttrj5P7upUTueSfoJcxEqa

agent/fc_agent/detectors.py

@@ -67,6 +67,37 @@ def nms_merge(boxes, iou_thresh: float = 0.6):
     return kept
 
 
+def dedupe_crops(pending, iou_thresh: float = 0.85):
+    """Greedy high-IoU dedupe over a list of (crop, region_template) pairs, run
+    just before the batched SigLIP embed so we never embed the same region twice.
+
+    Figure boxes are already NMS-merged and each YOLO self-NMSes, but the combined
+    per-frame pile (figure→concept ∪ anatomy component→concept ∪ panel) can still
+    carry genuine near-duplicates across proposers — e.g. a figure box that nearly
+    coincides with an anatomy component on a solo bust, or overlapping booru head
+    classes on one head. Those embed the same region twice, wasting GPU and a slot
+    against max_regions.
+
+    Boxes are compared ONLY within the same output kind and dropped when they
+    overlap at >= iou_thresh, keeping the highest-scoring one. The HIGH default
+    threshold is deliberate: it collapses only true near-identical boxes while
+    preserving intentional nested crops across scopes (a whole figure vs a small
+    head component sit well below it) and distinct kinds (concept vs panel). A
+    value >= 1.0 effectively disables it (nothing but an exact box matches)."""
+    kept = []
+    kept_boxes: dict = {}   # kind -> [bbox, ...] already kept
+    for crop, tmpl in sorted(
+        pending, key=lambda p: p[1].get("score") or 0.0, reverse=True
+    ):
+        bb = tmpl.get("bbox")
+        prior = kept_boxes.setdefault(tmpl.get("kind"), [])
+        if bb is not None and any(_iou(bb, kb) >= iou_thresh for kb in prior):
+            continue
+        prior.append(bb)
+        kept.append((crop, tmpl))
+    return kept
+
+
 class YoloProposer:
     """One lazily-loaded ultralytics YOLO. detect(image) → [(bbox_norm, score,
     label)] with bbox normalized (x, y, w, h) in [0,1]. Self-disables on any