fix KV API to unified format, and test

test/fixtures/generate-test-video.sh

@@ -0,0 +1,73 @@
+#!/bin/bash
+# Generate minimal test videos for FFprobe integration tests
+# Run inside Docker container with FFmpeg installed
+
+set -e
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+cd "$SCRIPT_DIR"
+
+echo "Generating test video files..."
+
+# 1. Simple video with video + audio streams (2 seconds, ~100KB)
+if [ ! -f "simple.mp4" ]; then
+    echo "Creating simple.mp4..."
+    ffmpeg -y -f lavfi -i testsrc=duration=2:size=320x240:rate=24 \
+           -f lavfi -i sine=frequency=440:duration=2 \
+           -c:v libx264 -preset ultrafast -crf 28 \
+           -c:a aac -b:a 64k \
+           -shortest \
+           simple.mp4
+fi
+
+# 2. Video with multiple audio tracks (for multi-stream testing)
+if [ ! -f "multi-audio.mkv" ]; then
+    echo "Creating multi-audio.mkv..."
+    ffmpeg -y -f lavfi -i testsrc=duration=2:size=640x480:rate=30 \
+           -f lavfi -i sine=frequency=440:duration=2 \
+           -f lavfi -i sine=frequency=880:duration=2 \
+           -c:v libx264 -preset ultrafast -crf 28 \
+           -filter_complex "[1:a]aformat=channel_layouts=stereo[a1];[2:a]aformat=channel_layouts=stereo[a2]" \
+           -map 0:v -map "[a1]" -map "[a2]" \
+           -c:a aac -b:a 64k \
+           -metadata:s:a:0 language=eng -metadata:s:a:0 title="English" \
+           -metadata:s:a:1 language=jpn -metadata:s:a:1 title="Japanese" \
+           multi-audio.mkv
+fi
+
+# 3. Video with subtitles (if possible, create with embedded subs)
+if [ ! -f "with-subs.mkv" ]; then
+    echo "Creating with-subs.mkv..."
+    # Create a simple SRT file
+    cat > temp_subs.srt << 'EOF'
+1
+00:00:00,000 --> 00:00:01,000
+Test subtitle line 1
+
+2
+00:00:01,000 --> 00:00:02,000
+Test subtitle line 2
+EOF
+
+    ffmpeg -y -f lavfi -i testsrc=duration=2:size=320x240:rate=24 \
+           -f lavfi -i sine=frequency=440:duration=2 \
+           -i temp_subs.srt \
+           -c:v libx264 -preset ultrafast -crf 28 \
+           -c:a aac -b:a 64k \
+           -c:s srt \
+           -metadata:s:s:0 language=eng \
+           with-subs.mkv
+
+    rm -f temp_subs.srt
+fi
+
+# 4. Audio-only file (should be skipped by FFmpeg plugin)
+if [ ! -f "audio-only.mp3" ]; then
+    echo "Creating audio-only.mp3..."
+    ffmpeg -y -f lavfi -i sine=frequency=440:duration=2 \
+           -c:a libmp3lame -b:a 128k \
+           audio-only.mp3
+fi
+
+echo "Test fixtures generated:"
+ls -la *.mp4 *.mkv *.mp3 2>/dev/null || true