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/tensor-delegate/ledger.yaml

@@ -0,0 +1,47 @@
+schema: superpaper.ledger/v1
+retired_ids: []
+paper:
+  id: tensor-delegate
+  title: Head scores
+  authors: ["Fixture"]
+  notes_language: zh
+  source: {kind: excerpt}
+coverage:
+  mode: excerpt
+questions:
+  - {id: Q1, text: "每头打分沿哪一维收缩？", source: "excerpt"}
+claims:
+  - id: C1
+    text: "每头打分沿 d_h 收缩；K^T 必须物理换面"
+    kind: theoretical
+    status: core
+    supports: [Q1]
+definitions: []
+assumptions: []
+lemmas: []
+symbols:
+  - {name: Q, latex: "Q", meaning: "query", kind: value}
+  - {name: K, latex: "K", meaning: "key", kind: value}
+  - {name: S, latex: "S", meaning: "score", kind: score}
+  - {name: dh, latex: "d_h", meaning: "头维", kind: "shape parameter"}
+derivations:
+  - id: DER1
+    claim: C1
+    title: "打分"
+    expand: true
+    figure: null
+    steps:
+      - {id: S1, from: "Q K", to: "Q K^{\\top}", rule: rearrange}
+figures:
+  - id: F2
+    claim: C1
+    title: "每头打分"
+    grammar: tensor-face
+    toolkit: supertensor
+    signals: [axis, shape, transpose, contraction, face]
+    request: figures/F2/F2.request.md
+    include: figures/F2/build/F2.pdf
+    status: included
+evidence: []
+terms: []
+source_assets: []