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.

examples/pipeline-delegate/ledger.yaml

@@ -0,0 +1,47 @@
+schema: superpaper.ledger/v1
+retired_ids: []
+paper:
+  id: pipeline-delegate
+  title: A One-Step Predictor
+  authors: ["Fixture"]
+  notes_language: zh
+  source: {kind: excerpt}
+coverage:
+  mode: excerpt
+  sections_in: ["1"]
+questions:
+  - {id: Q1, text: "前向主路和损失如何分开？", source: "excerpt"}
+claims:
+  - id: C1
+    text: "一次前向是 x → f_θ → ŷ；损失不在主路上"
+    kind: contribution
+    status: core
+    supports: [Q1]
+definitions: []
+assumptions: []
+lemmas: []
+symbols:
+  - {name: x, latex: "x", meaning: "输入", kind: value}
+  - {name: yhat, latex: "\\hat y", meaning: "预测", kind: value}
+  - {name: L, latex: "L", meaning: "损失", kind: scalar}
+derivations:
+  - id: DER1
+    claim: C1
+    title: "前向定义"
+    expand: true
+    figure: null
+    steps:
+      - {id: S1, from: "x", to: "f_\\theta(x)=\\hat y", rule: definition}
+figures:
+  - id: F1
+    claim: C1
+    title: "一次前向与侧路损失"
+    grammar: pipeline
+    toolkit: superfig
+    signals: [pipeline, what-eats-what]
+    request: figures/F1/F1.request.md
+    include: figures/F1/build/F1.pdf
+    status: included
+evidence: []
+terms: []
+source_assets: []