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.

references/figure-request.md

@@ -0,0 +1,11 @@
+# Figure request
+
+Sibling figure agents see only `notes/figures/F*/F*.request.md` plus that sibling `SKILL.md`. They do not read `ledger.yaml`.
+
+- superfig: `\sfnode` keys `role, level, gap, bracket, at=`. `\sfconn` has no endpoints. `at` must be TikZ calc with `($…$)`.
+- supertensor: every `ststack` / `stface` / `stglyph` has `coord: ""`.
+- `allow-raw-tikz` must also appear as `% superfig-lint: allow-raw-tikz` in the `.tex`.
+- Build: `superfig/scripts/build.sh F1.tex F1/build` (second arg is the outdir).
+- Screenshots: `scripts/screenshot.sh --work <work> --id F2` (`pdftoppm -r 200`, then optional `crop_bbox`).
+
+Worked files: `examples/pipeline-delegate/notes/figures/F1/F1.request.md`, `examples/tensor-delegate/notes/figures/F2/F2.request.md`.