fix: two long-running HLS transcode issues (#355)

* fix: release targets from Output._targets on finalize

Long-running HLS transcodes leak memory. Every finalized BufferTarget
stays in _targets until the outer Output closes, pinning its buffer.
Writer.finalize() already does this cleanup for writer-based flows;
extend it to buffer-finalize paths via the public 'finalized' event.

* fix: ReadOrchestrator LRU eviction picks only drained workers

assert(pendingSlices.length === 0) fires under heavy concurrent reads
(e.g. multi-rendition HLS decode from BlobSource). LRU filter only
checked !running; workers with queued slices could be evicted.
Add pendingSlices.length === 0 to the filter.

* fix: export AppendOnlyStreamTarget from index

Missing from the re-export; public docs import it by name.

* fix: join HLS init segment path with root + playlist path

Init path went through _getTarget bare; segments got joined with rootPath + playlist.path. Playlist-relative URI then can't resolve when the playlist lives in a subdirectory.

* Fix targets not being cleaned up, fix paused workers with remaining pending slices, modify doc block, fixed isRoot not being changed on proxied requests

---------

Co-authored-by: Vanilagy <[email protected]>

test/node/hls-input.test.ts

@@ -948,3 +948,24 @@ test.concurrent('Widevine encryption (SAMPLE-AES-CTR) succeeds with buffer keys'
 	assert(lastPacket);
 	expect(lastPacket.timestamp + lastPacket.duration).toBe(60);
 });
+
+test.concurrent('SourceRequest.isRoot', async () => {
+	using input = new Input({
+		source: new CustomPathedSource(
+			'https://test-streams.mux.dev/x36xhzz/x36xhzz.m3u8',
+			({ path, isRoot }) => {
+				if (isRoot) {
+					expect(path).toBe('https://test-streams.mux.dev/x36xhzz/x36xhzz.m3u8');
+				}
+
+				return new UrlSource(path);
+			},
+		),
+		formats: ALL_FORMATS,
+	});
+
+	const videoTrack = await input.getPrimaryVideoTrack();
+	assert(videoTrack);
+
+	await videoTrack.computeDuration();
+});

test/node/hls-output.test.ts

@@ -2903,3 +2903,37 @@ test('Append-only stream with monotonicity violation', async () => {
 	await expect(source.add(new EncodedPacket(avcPacketData, 'key', 2, 0), avcMetadata))
 		.rejects.toThrow('AppendOnlyStreamTarget');
 });
+
+test('Relative paths & isRoot', async () => {
+	const output = new Output({
+		format: new HlsOutputFormat({
+			segmentFormat: new CmafOutputFormat(),
+			getPlaylistPath: () => `a/folder/playlist.m3u8`,
+		}),
+		target: new PathedTarget('path/to/master.m3u8', (request) => {
+			if (request.isRoot) {
+				expect(request.path).toBe('path/to/master.m3u8');
+			} else {
+				expect(request.path.startsWith('path/to/a/folder/')).toBe(true);
+			}
+
+			return new BufferTarget();
+		}),
+	});
+
+	const source = videoSource();
+	output.addVideoTrack(source);
+
+	await output.start();
+
+	await source.add(new EncodedPacket(avcPacketData, 'key', 0, 0), avcMetadata);
+	await source.add(new EncodedPacket(avcPacketData, 'delta', 0.5, 0), avcMetadata);
+	await source.add(new EncodedPacket(avcPacketData, 'delta', 1, 0), avcMetadata);
+	await source.add(new EncodedPacket(avcPacketData, 'delta', 1.5, 0), avcMetadata);
+	await source.add(new EncodedPacket(avcPacketData, 'key', 2, 0), avcMetadata);
+	await source.add(new EncodedPacket(avcPacketData, 'delta', 2.5, 0), avcMetadata);
+	await source.add(new EncodedPacket(avcPacketData, 'delta', 3, 0), avcMetadata);
+	await source.add(new EncodedPacket(avcPacketData, 'delta', 3.5, 0), avcMetadata);
+
+	await output.finalize();
+});