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).

src/store/graph.ts

@@ -83,8 +83,8 @@ const isProvenancePoint = (v: unknown): v is ProvenancePoint =>
 const isGraphNode = (v: unknown): v is GraphNode =>
 	isRecord(v) &&
 	isString(v.id) &&
+	isString(v.name) &&
 	isString(v.statement) &&
-	isString(v.description) &&
 	Array.isArray(v.aliases) &&
 	v.aliases.every(isString) &&
 	isString(v.createdAt) &&