Node schema pivot: short name (label) + full-precision statement; description dropped

With real extracted data, full-sentence statements as canvas labels proved
unworkable: 10-line label blocks, illegible overprint clusters, bottom-edge
clipping. Per the user's 2026-09-08 decision:

- GraphNode/ExtractedProposition gain `name` — a very short, glanceable
  label (glossary-headword style: "Will to power"), presentational only:
  not unique, not identity, never precise. Set at creation; link-appends
  never change it (first line defines; labels stay stable across sessions).
- `statement` keeps its full precision and becomes the identity anchor;
  the detail card shows it under the name. `description` is dropped.
- Extractor coins the name (freshest session context); auditor carries it
  through on create, rewording only clearly unglanceable names; linked
  propositions keep the existing node's name.
- Renderer: canvas label = name; search matches name + statement;
  detail card = name (bold) + statement (muted).
- Store guard requires name (pre-pivot node lines are skipped as legacy);
  vision.md node-schema bullet + amendments table updated (2026-09-08).

tests/extraction.test.ts

@@ -135,8 +135,8 @@ const FINDINGS: SessionFindings = {
 	propositions: [
 		{
 			id: "p1",
+			name: "Derivative",
 			statement: "The derivative measures how fast a function changes",
-			description: "The derivative of a function at a point is its instantaneous rate of change there.",
 			aliases: [],
 			messages: ["a2"],
 			evidence: ["TEACHER [a2]: The derivative measures how fast a function changes."],
@@ -144,8 +144,8 @@ const FINDINGS: SessionFindings = {
 		},
 		{
 			id: "p2",
-			statement: "Chain rule intuition",
-			description: "The chain rule differentiates composed functions by multiplying local rates.",
+			name: "Chain rule",
+			statement: "The chain rule differentiates composed functions by multiplying local rates.",
 			aliases: [],
 			messages: ["a2"],
 			evidence: ["LEARNER [u1]: teach me the chain rule"],
@@ -267,8 +267,8 @@ describe("the extraction pipeline (extractor → auditor → merger)", () => {
 		const existingId = "n_existing";
 		ledgers.appendNode({
 			id: existingId,
+			name: "Derivative",
 			statement: "Derivatives measure rates of change",
-			description: "Pre-existing node from an earlier session.",
 			aliases: [],
 			createdAt: "2026-08-01T00:00:00.000Z",
 			provenance: [],