test: committed replay fixtures from the public-domain corpus

Five HDF5 embedding dumps from bali/ — Road to Bali (1952) — 3.6 MB total,
generated at 5 fps with a 32 px minimum face. CI never calls a model, so
inference happens on a GPU host and CI replays these as data; everything
downstream of embedding is cheap CPU maths.

Public domain is the reason this corpus rather than a convenient one: derived
fixtures can be committed, where anything cut from a copyrighted title could not
live in the repository at all.

The set covers distinct behaviours rather than being five of the same thing:
bali_28 has 9 cuts, so it exercises shot/reverse-shot association (AR-007);
bali_46 is sparse at 140 faces over 385 frames, so it exercises gaps and
extinction (AR-013); bali_13 is the busiest at 4 faces per frame; bali_31 is
short at 29s. All five recorded zero drops.

Both pinned parameters are consequences of measurements, not defaults: 5 fps
because 1 fps over a 77s clip is 77 frames, too thin for an extinction window
measured in tens of seconds; 32 px because that is the VR-005 floor, and the
corpus is 480x360 so a stricter value would reject most of what is there.

make_fixtures.sh regenerates them. Reproducibility is the requirement — a
fixture whose provenance is unknown is worse than none, because it will be
trusted. These are byte-reproducible only because of AR-004: before node
outputs blocked rather than dropped, the same command produced different dumps
run to run.

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

TRACES: VR-001 | PR-002

scripts/make_fixtures.sh

@@ -0,0 +1,60 @@
+#!/usr/bin/env bash
+# make_fixtures.sh — regenerate the committed replay fixtures.
+#
+# TRACES: VR-001 | PR-002
+#
+# CI never calls a model (see docs/requirements.md, "CI never calls a model"):
+# the embedder is impractical on the N100 CI host, so inference happens HERE, on
+# a machine with a GPU, and CI consumes the HDF5 dumps as data. Everything
+# downstream of embedding — tracking, presence windows, belief accumulation,
+# expansion — is cheap CPU maths and replays from these files.
+#
+# Reproducibility is a requirement, not a nicety. A fixture whose provenance is
+# unknown is worse than no fixture, because it will be trusted. Every parameter
+# that affects the output is pinned below rather than left to a default, and the
+# dumps carry the embedder identity and SHA-256 (GR-004) so a replay cannot be
+# silently scored against the wrong gallery.
+#
+# These are byte-reproducible only because node outputs block rather than drop
+# on a full channel (AR-004). Before that fix the same command produced
+# different dumps run to run, since what got dropped depended on timing.
+#
+# Source: bali/ — Road to Bali (1952), public domain. That matters: derived
+# fixtures can be committed, where anything cut from a copyrighted title could
+# not live in the repository at all.
+set -euo pipefail
+
+REPO="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+CLIPS="${CLIPS:-$REPO/../bali}"
+GALLERY="${GALLERY:-$REPO/gallery_lvface.h5}"
+BIN="${BIN:-$REPO/build/scene_analyze}"
+OUT="$REPO/tests/fixtures/dumps"
+
+# Pinned. Changing either invalidates every committed fixture.
+#   fps 5      — 1 fps over a 77 s clip is 77 frames, too thin to exercise an
+#                extinction window measured in tens of seconds.
+#   min-face   — 32 px, the VR-005 measured floor (98.1% TPI). The corpus is
+#                480x360, so a stricter value would reject most faces present.
+FPS=5
+MIN_FACE_PX=32
+
+[[ -x "$BIN"      ]] || { echo "no scene_analyze at $BIN (set BIN=)" >&2; exit 1; }
+[[ -f "$GALLERY"  ]] || { echo "no gallery at $GALLERY (set GALLERY=)" >&2; exit 1; }
+[[ -d "$CLIPS"    ]] || { echo "no clips at $CLIPS (set CLIPS=)" >&2; exit 1; }
+
+mkdir -p "$OUT"
+
+for clip in "$CLIPS"/Road_To_Bali-*.webm; do
+    n="$(basename "$clip" .webm)"; n="${n##*-}"
+    echo "── bali_$n"
+    "$BIN" --movie "$clip" --gallery "$GALLERY" \
+           --fps "$FPS" --min-face-px "$MIN_FACE_PX" \
+           --dump-embeddings "$OUT/bali_$n.h5" \
+           --output /dev/null 2>&1 | grep -E "wrote|dropped" || true
+done
+
+echo
+echo "Regenerated in $OUT — verify the diff is empty if nothing upstream changed."
+echo "A non-empty diff means detection, alignment or embedding moved. That is"
+echo "either a regression or a deliberate change, and either way the golden"
+echo "outputs derived from these fixtures need reviewing."