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/sae_embed_loader.py

@@ -33,4 +33,14 @@ def load_embedder(build_dir: str, models_dir: str, arcface: str | None = None,
         if not Path(model).is_file():
             sys.exit(f"{name} model not found: {model}\nRun: bash scripts/download_models.sh")
 
-    return sae_embed.FaceEmbedder(detector_path, arcface_path, conf, nms, max_side)
+    # A TRT-backend build cannot load .onnx; it needs pre-built engines from
+    # scripts/build_trt_engines.sh. Pass them when present (ignored by ORT).
+    trt = Path(models_path).parent / "trt_cache"
+    det_engine = trt / "scrfd.scrfd_500m_bnkps.640.fp16.engine"
+    arc_engine = trt / f"arcface.{Path(arcface_path).stem}.b4.fp16.engine"
+
+    return sae_embed.FaceEmbedder(
+        detector_path, arcface_path, conf, nms, max_side,
+        str(det_engine) if det_engine.is_file() else "",
+        str(arc_engine) if arc_engine.is_file() else "",
+    )