Add intermediate character assets and promo conversion script for mog-showdown

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

examples/mog-showdown/scripts/convert-highfps.sh

@@ -0,0 +1,40 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Speed up a slow-mo Playwright recording to produce high-FPS output.
+# Usage: convert-highfps.sh <input.webm> <output.mp4> [slow_mo_factor]
+#
+# Technique: Playwright recordVideo caps at 25 FPS. By recording the game
+# at half speed (0.5x) for 2x duration, then speeding up here, we get
+# effective 50 FPS output.
+
+INPUT="${1:?Usage: convert-highfps.sh <input> <output> [factor]}"
+OUTPUT="${2:?Usage: convert-highfps.sh <input> <output> [factor]}"
+FACTOR="${3:-0.5}"
+
+if [ ! -f "$INPUT" ]; then
+  echo "Error: input file not found: $INPUT" >&2
+  exit 1
+fi
+
+OUTPUT_FPS=$(echo "25 / $FACTOR" | bc)
+
+echo "Converting: $INPUT -> $OUTPUT"
+echo "  Factor: ${FACTOR} | Output FPS: ${OUTPUT_FPS}"
+
+ffmpeg -y -i "$INPUT" \
+  -vf "setpts=${FACTOR}*PTS" \
+  -r "$OUTPUT_FPS" \
+  -c:v libx264 -preset fast -crf 23 -pix_fmt yuv420p \
+  -movflags +faststart -an \
+  "$OUTPUT"
+
+echo ""
+echo "Verifying output..."
+DURATION=$(ffprobe -v quiet -show_entries format=duration -of csv=p=0 "$OUTPUT")
+ACTUAL_FPS=$(ffprobe -v quiet -select_streams v:0 -show_entries stream=r_frame_rate -of csv=p=0 "$OUTPUT")
+
+echo "  Duration: ${DURATION}s"
+echo "  Frame rate: ${ACTUAL_FPS}"
+echo "  File size: $(du -h "$OUTPUT" | cut -f1)"
+echo "Done."