Wave 7 chunk B: remove the embeddings machinery — the ladder collapses

The owner's wave-7 ruling: embeddings die entirely (git history is the
stash); clustering is birth-session derived (chunk A, 950ddfd), labels
are session names, and the prober's graph tools replace injection.

- settings: GraphSettings collapses to { enabled } — embedding,
  embeddingModel, clustering, labeling all die. Migration story: stale
  record keys are UNREAD and dropped by the sanitizer's reconstruction;
  the next graph-section PUT (replace-whole) persists the collapsed
  shape. The settings-panel GraphSection renders one master row.
- deleted: src/server/embeddings.ts (adapters, resolveEmbeddingPortFor,
  embedNewNodes, embeddingPort, embeddingModelCatalog), the
  GET /api/models/embeddings route, scripts/embed-graph.ts, tests for
  all three, and the /api/models/embeddings picker surfaces in the UI.
- prices: EMBEDDING_PRICES overlay + callCost fallback die. cost-summary:
  the embedding stage fold dies — back to three stages (extraction/
  audit/naming) per the owner ruling; historical stages.embedding spend
  in old run records is simply not displayed.
- ports: EmbeddingPort/EmbeddingResult/EmbeddingTask die. The embeddings
  LEDGER surface (readEmbeddings/writeEmbeddings + EmbeddingsLedger +
  EMBEDDINGS_FILE + graph-deletion's vector pruning) STAYS — inert data,
  kept only so graph-context.ts compiles until Teacher's pass removes
  it; the seam dies in the follow-up interlude.
- chat-handler (approved cross-lane unwiring, wave-6 precedent): the
  extraction pipeline's embedder becomes a documented no-op (nothing
  embedded, nothing spent, ledger untouched) until Teacher's pass
  removes the phase; the graph-context injection dispatch gate, the
  graphContext deps wiring, the setContextRespawn seam, and
  turn-service's triggerGraphContext are gone — injection is dead
  code pending Teacher's file deletions.
- scripts: backfill-graph/import-notes pass the same no-op embedder;
  replay-layout derives clusters from birthSessionPartition (the same
  partition the real settle uses) instead of the embeddings ledger.
- settings-body: parseGraphSettingsBody reads the master switch only —
  old-shape keys in a body are ignored, not rejected; bad shapes 400.
- next.config: the @huggingface tracing-exclusion guards die with the
  last reference.

Cross-lane flags: extraction.ts/graph-context.ts keep stale embed
comments + the embed phase until Teacher's full pass (their parallel
interlude owns those files — zero overlap kept by design);
semantic-clusters.ts + its test stay one more round (extraction.test.ts,
Teacher's file, still imports it — they delete it with the namer cases);
ChatSettings.graphContextTokens + the graph-context-control UI stay
until Teacher+UI.

Gates: tsc clean, eslint clean, 885/885 tests, build compiles.
Live-verified on the port-3004 dev tree: PUT /api/settings/graph with
dead keys collapses on write, bad shapes 400, GET reads {enabled: true},
/api/models/embeddings 404s.

tests/settings-resolution.test.ts

@@ -11,7 +11,6 @@ import assert from "node:assert/strict";
 import { describe, it } from "node:test";
 import {
 	extractionEnabled,
-	graphContextEnabled,
 	graphToolsEnabled,
 	resolveConversationSpec,
 	resolveModelSpec,
@@ -43,7 +42,7 @@ describe("resolveSettings", () => {
 		assert.equal(eff.appearance.proseFontSize, 16);
 		assert.equal(eff.appearance.sessionNameSerif, true);
 		assert.equal(eff.appearance.mdRendering.headingWeight, 900);
-		assert.deepEqual(eff.graph, { enabled: true, embedding: true, clustering: true, labeling: true, embeddingModel: null }); // BYOK wave 6: no factory embedding model
+		assert.deepEqual(eff.graph, { enabled: true }); // wave 7 collapse: the master switch ONLY
 	});
 
 	it("explicit record values win over every factory default", () => {
@@ -76,9 +75,8 @@ describe("resolveSettings", () => {
 		assert.equal(eff.appearance.mode, "light");
 		assert.equal(eff.appearance.proseFontSize, 20);
 		assert.equal(eff.appearance.mdRendering.headingWeight, 600);
-		// graph: enabled=false explicit; absent rungs stay factory-on (stored
-		// but inert — the ladder grays them out in the UI).
-		assert.deepEqual(eff.graph, { enabled: false, embedding: true, clustering: true, labeling: true, embeddingModel: null }); // wave 6: unset embeddingModel resolves to the null floor
+		// wave 7 collapse: the section IS the master switch.
+		assert.deepEqual(eff.graph, { enabled: false });
 	});
 
 	it("partial role override: thinkingLevel alone borrows the SLOT's model (or nothing, without one)", () => {
@@ -224,29 +222,20 @@ describe("resolveConversationSpec (the turn gate's chain)", () => {
 });
 
 describe("the graph channel gates (the wave's seam honoring)", () => {
-	it("WRITE channel (extraction): dies with the master switch only", () => {
-		assert.equal(extractionEnabled({ enabled: true, embedding: true, clustering: true, labeling: true, embeddingModel: null }), true);
-		assert.equal(extractionEnabled({ enabled: true, embedding: false, clustering: false, labeling: false, embeddingModel: null }), true);
-		assert.equal(extractionEnabled({ enabled: false, embedding: true, clustering: true, labeling: true, embeddingModel: null }), false);
+	it("WRITE channel (extraction): dies with the master switch — the ONLY graph setting since wave 7", () => {
+		assert.equal(extractionEnabled({ enabled: true }), true);
+		assert.equal(extractionEnabled({ enabled: false }), false);
 	});
 
-	it("READ channel (graph-context): needs master AND the embedding rung", () => {
-		assert.equal(graphContextEnabled({ enabled: true, embedding: true, clustering: false, labeling: false, embeddingModel: null }), true);
-		assert.equal(graphContextEnabled({ enabled: true, embedding: false, clustering: true, labeling: true, embeddingModel: null }), false);
-		assert.equal(graphContextEnabled({ enabled: false, embedding: true, clustering: true, labeling: true, embeddingModel: null }), false);
-	});
-
-	it("both gates ride resolveSettings' factory defaults (all on → both open)", () => {
+	it("the write gate rides resolveSettings' factory defaults (all on → open)", () => {
 		const eff = resolveSettings(null);
 		assert.equal(extractionEnabled(eff.graph), true);
-		assert.equal(graphContextEnabled(eff.graph), true);
 		const off = resolveSettings({ version: 1, graph: { enabled: false } });
 		assert.equal(extractionEnabled(off.graph), false);
-		assert.equal(graphContextEnabled(off.graph), false);
 	});
 
 	it("PROBER GRAPH TOOLS gate (wave 7, owner ruling 2026-09-23): the agent toggle AND the graph master switch compose", () => {
-		const graph = { enabled: true, embedding: true, clustering: true, labeling: true, embeddingModel: null };
+		const graph = { enabled: true };
 		assert.equal(graphToolsEnabled({ graph, agent: { graphTools: {} } }), true, "absent subsection = ON");
 		assert.equal(graphToolsEnabled({ graph, agent: { graphTools: { enabled: true } } }), true);
 		assert.equal(graphToolsEnabled({ graph, agent: { graphTools: { enabled: false } } }), false);