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/fanout-copy.sh

@@ -0,0 +1,36 @@
+#!/usr/bin/env bash
+# Fan-out: read pre-encoded FLV from pipe → RTMP sinks (stream copy, no re-encode).
+set -euo pipefail
+
+ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+# shellcheck disable=SC1091
+source "${ROOT}/lib/common.sh"
+# shellcheck disable=SC1091
+source "${ROOT}/lib/outputs.sh"
+
+require_cmd "${FFMPEG_BIN}"
+ensure_storage
+ensure_pipe
+
+TEE_SPEC="$(build_fanout_tee_spec)"
+LOG_FILE="${STORAGE_DIR}/fanout.log"
+MAX_RETRIES="${FANOUT_RETRIES:-5}"
+attempt=0
+
+log "fanout → ${#SINKS[@]} sink(s)"
+
+while [[ "${attempt}" -le "${MAX_RETRIES}" ]]; do
+  attempt=$((attempt + 1))
+  log "fanout attempt ${attempt}/${MAX_RETRIES}"
+  if "${FFMPEG_BIN}" -hide_banner -loglevel info \
+      -thread_queue_size "${THREAD_QUEUE_SIZE}" \
+      -i "${PIPE_PATH}" \
+      -map 0 \
+      -c copy \
+      -f tee "${TEE_SPEC}" >> "${LOG_FILE}" 2>&1; then
+    log "fanout finished normally"
+    break
+  fi
+  warn "fanout ffmpeg exited — retrying after pipe flush"
+  sleep 1
+done