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-body.test.ts

@@ -150,47 +150,25 @@ describe("parseAppearanceSettingsBody", () => {
 });
 
 describe("parseGraphSettingsBody", () => {
-	it("parses the four-rung ladder replace-whole", () => {
-		const r = parseGraphSettingsBody({ enabled: false, embedding: false });
+	it("parses the collapsed section replace-whole (wave 7: the master switch ONLY)", () => {
+		const r = parseGraphSettingsBody({ enabled: false });
 		assert.ok(r.ok);
-		assert.deepEqual(r.settings, { enabled: false, embedding: false });
+		assert.deepEqual(r.settings, { enabled: false });
 		assert.equal(parseGraphSettingsBody({}).ok, true);
 	});
 
-	it("rejects non-boolean rungs and unknown bodies", () => {
+	it("rejects non-boolean switches and unknown bodies", () => {
 		assert.equal(parseGraphSettingsBody({ enabled: "off" }).ok, false);
 		assert.equal(parseGraphSettingsBody("nope").ok, false);
 	});
 
-	it("the ladder DEPENDENCY (graph → embedding → clustering → labeling) is a UI concern, not a parse concern", () => {
-		// Nothing stops a stored {enabled: false, labeling: true} — the
-		// values persist but resolve inert (grays out in the panel).
+	it("the dead wave-6 rungs in a body are ignored — the section collapses on write", () => {
+		// Old clients may still send {embedding: true, embeddingModel: …};
+		// the parser reads ONLY the master switch — the dead keys are not
+		// an error, they are just not part of the section anymore.
 		const r = parseGraphSettingsBody({ enabled: false, clustering: true, labeling: true });
 		assert.ok(r.ok);
-	});
-
-	it("embeddingModel (wave 6): null or a shipped-provider slug; anything else is a 400", () => {
-		const nulled = parseGraphSettingsBody({ embeddingModel: null });
-		assert.ok(nulled.ok);
-		assert.deepEqual(nulled.settings, { embeddingModel: null });
-		for (const slug of [
-			"openai:text-embedding-3-small",
-			"openrouter:openai/text-embedding-3-large",
-			"google:gemini-embedding-001",
-			// OpenRouter ids may carry a :free-style suffix — the provider is
-			// the part before the FIRST colon (live catalog fact, 2026-09-23).
-			"openrouter:liquid/lfm-2.5-embedding-350m:free",
-		]) {
-			const r = parseGraphSettingsBody({ embeddingModel: slug });
-			assert.ok(r.ok, slug);
-			assert.deepEqual(r.settings, { embeddingModel: slug });
-		}
-		// Bad shapes never become a live model.
-		assert.equal(parseGraphSettingsBody({ embeddingModel: "text-embedding-3-small" }).ok, false, "no provider prefix");
-		assert.equal(parseGraphSettingsBody({ embeddingModel: "bedrock:whatever" }).ok, false, "unshipped provider");
-		assert.equal(parseGraphSettingsBody({ embeddingModel: "openai:" }).ok, false, "empty id");
-		assert.equal(parseGraphSettingsBody({ embeddingModel: 42 }).ok, false, "non-string");
-		assert.equal(parseGraphSettingsBody({ embeddingModel: "openai:has spaces" }).ok, false, "whitespace id");
+		assert.deepEqual(r.settings, { enabled: false });
 	});
 });