Add lab restream pipeline with pirate_drift logo and lib/env.sh.

Encode-once/fanout scripts, HLS output, and single overloadable env source.
Commits assets/pirate_drift.png as default watermark for cluster runs.

Co-authored-by: Cursor <cursoragent@cursor.com>

bin/encode-only.sh

@@ -0,0 +1,81 @@
+#!/usr/bin/env bash
+# Encode once → local recording (+ optional HLS). No named-pipe fanout stage.
+set -euo pipefail
+
+ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+# shellcheck disable=SC1091
+source "${ROOT}/lib/common.sh"
+# shellcheck disable=SC1091
+source "${ROOT}/lib/source.sh"
+# shellcheck disable=SC1091
+source "${ROOT}/lib/filters.sh"
+# shellcheck disable=SC1091
+source "${ROOT}/lib/outputs.sh"
+
+resolve_source "${1:-}"
+require_cmd "${FFMPEG_BIN}"
+require_logo
+ensure_storage
+
+compute_layout() {
+  VIDEO_INPUT="0:v"
+  if [[ ${#AUDIO_INPUT_ARGS[@]} -gt 0 ]]; then
+    AUDIO_MAP_INPUT=1
+    LOGO_INPUT=2
+  else
+    AUDIO_MAP_INPUT=0
+    LOGO_INPUT=1
+  fi
+}
+
+compute_layout
+RECORD_PATH="$(next_record_path)"
+LOG_FILE="${STORAGE_DIR}/encode.log"
+build_filter_complex "${VIDEO_INPUT}" "${LOGO_INPUT}:v"
+MAP_V="$(map_video_out)"
+MAP_A="$(map_audio_out)"
+
+build_record_tee() {
+  local record="$1"
+  local parts=()
+  parts+=("$(file_tee_entry "${record}")")
+  if [[ -n "${HLS_OUTPUT_DIR}" ]]; then
+    parts+=("$(hls_tee_entry "${HLS_OUTPUT_DIR}")")
+  fi
+  local IFS='|'
+  echo "${parts[*]}"
+}
+
+TEE_SPEC="$(build_record_tee "${RECORD_PATH}")"
+
+run_ffmpeg() {
+  "${FFMPEG_BIN}" -hide_banner -loglevel info \
+    -rtbufsize 256M -probesize 100M -analyzeduration 250M \
+    "$@" \
+    -i "${LOGO_PATH}" \
+    "${FFMPEG_TS_FLAGS[@]}" \
+    -filter_complex "${FILTER_COMPLEX}" \
+    -map "${MAP_V}" -map "${MAP_A}" \
+    -threads "${THREADS}" -framerate "${FPS}" -r "${FPS}" \
+    -s "${RES}" ${VCODEC} ${PRESET} ${BITRATE} ${ACODEC} -bufsize "${BUFSIZE}" \
+    -f tee "${TEE_SPEC}" >> "${LOG_FILE}" 2>&1
+}
+
+log "encode-only → ${RECORD_PATH}"
+[[ -n "${HLS_OUTPUT_DIR}" ]] && log "HLS → ${HLS_OUTPUT_DIR}"
+
+if [[ "${USE_YTDLP}" == "1" ]]; then
+  require_cmd "${YTDLP_BIN}"
+  mapfile -d '' -t YTDLP_CMD < <(build_ytdlp_pipeline)
+  "${YTDLP_CMD[@]}" 2>>"${LOG_FILE}" | \
+    run_ffmpeg -thread_queue_size "${THREAD_QUEUE_SIZE}" -i pipe:0 \
+      "${AUDIO_INPUT_ARGS[@]}"
+else
+  read_rate_flag
+  run_ffmpeg \
+    "${RE_FLAG[@]}" \
+    -thread_queue_size "${THREAD_QUEUE_SIZE}" \
+    -reconnect_on_network_error 1 -reconnect_streamed 1 -reconnect_delay_max 5 \
+    -i "${SOURCE_URL}" \
+    "${AUDIO_INPUT_ARGS[@]}"
+fi