feat: land superpaper v1 notes scaffold

Add the ledger schema, class router, lint codes, ingest/build
pipeline, and three work-tree examples: align derivation,
superfig delegation, and supertensor delegation.

scripts/screenshot.sh

@@ -0,0 +1,61 @@
+#!/usr/bin/env bash
+# Raster one ledger figure from paper.pdf via pdftoppm. crop_bbox is 200 dpi page pixels.
+set -euo pipefail
+
+ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+WORK=""
+FID=""
+while [[ $# -gt 0 ]]; do
+  case "$1" in
+    --work|--out) WORK="$2"; shift 2 ;;
+    --id) FID="$2"; shift 2 ;;
+    *) echo "usage: screenshot.sh --work DIR --id F2" >&2; exit 2 ;;
+  esac
+done
+[[ -n "$WORK" && -n "$FID" ]] || { echo "need --work and --id" >&2; exit 2; }
+
+"$ROOT/scripts/python" - "$WORK" "$FID" <<'PY'
+import sys, tempfile, subprocess, shutil
+from pathlib import Path
+import yaml
+
+work = Path(sys.argv[1])
+fid = sys.argv[2]
+ledger = yaml.safe_load((work / "ledger.yaml").read_text())
+fig = next((f for f in (ledger.get("figures") or []) if f.get("id") == fid), None)
+if fig is None:
+    sys.exit(f"no figure {fid}")
+pages = fig.get("source_pages") or []
+if not pages:
+    sys.exit("source_pages required")
+n = int(pages[0])
+pdf = work / "source" / "paper.pdf"
+if not pdf.is_file():
+    sys.exit(f"missing {pdf}")
+dest_dir = work / "notes" / "figures" / fid
+dest_dir.mkdir(parents=True, exist_ok=True)
+dest = dest_dir / "orig.png"
+bbox = fig.get("crop_bbox")
+with tempfile.TemporaryDirectory() as td:
+    prefix = Path(td) / "pg"
+    subprocess.run(
+        ["pdftoppm", "-png", "-r", "200", "-f", str(n), "-l", str(n), str(pdf), str(prefix)],
+        check=True,
+    )
+    produced = sorted(Path(td).glob("pg*.png"))
+    if not produced:
+        sys.exit("pdftoppm produced no page")
+    page = produced[0]
+    if bbox is None:
+        shutil.copy2(page, dest)
+    else:
+        if shutil.which("magick") is None:
+            sys.exit("crop_bbox set but magick is missing")
+        x0, y0, x1, y1 = bbox
+        w, h = int(x1 - x0), int(y1 - y0)
+        subprocess.run(
+            ["magick", str(page), "-crop", f"{w}x{h}+{int(x0)}+{int(y0)}", "+repage", str(dest)],
+            check=True,
+        )
+print(dest)
+PY