fix(trt): drop explicit shapes for static TransNetV2; gallery over-fetch + dedup

trtexec rejects --minShapes/--optShapes/--maxShapes for a fully static model
("Static model does not take explicit shapes"). TransNetV2's input is fixed at
1x100x27x48x3, so the shape comes from the model itself.

Gallery build now over-fetches TMDB/Wikidata candidates by a configurable
factor: near-duplicate stills (the same photo at different crops or
resolutions) are discarded after embedding, so downloading exactly
images_per_actor left actors short of that many *distinct* embeddings.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

scripts/build_trt_engines.sh

@@ -76,14 +76,14 @@ if [[ -f "$SCENE_MODEL" ]]; then
     echo "== TransNetV2 (scene detector) =="
     # Fixed 1x100x27x48x3 window. The raw-TRT scene detector backend loads this
     # engine directly via --scene-detector-engine; the ORT-TRT EP builds its own.
-    SCENE_IN="$(input_name "$SCENE_MODEL")"
-    echo "   (input tensor: $SCENE_IN)"
+    # No --*Shapes here: TransNetV2's input is fully static (1x100x27x48x3
+    # with no dynamic dimensions), and TensorRT rejects explicit shape
+    # profiles for such a model — "Static model does not take explicit shapes
+    # since the shape of inference tensors will be determined by the model
+    # itself". The shape comes from the model.
     run trtexec \
         --onnx="$SCENE_MODEL" \
         --fp16 \
-        --minShapes="$SCENE_IN":1x100x27x48x3 \
-        --optShapes="$SCENE_IN":1x100x27x48x3 \
-        --maxShapes="$SCENE_IN":1x100x27x48x3 \
         --saveEngine="$OUT/transnetv2.100x27x48.fp16.engine" \
         --useCudaGraph
 else