diff --git a/README.md b/README.md
index 969a3f9..2cac04d 100644
--- a/README.md
+++ b/README.md
@@ -21,10 +21,6 @@ npm test             # all tests (node:test via tsx; deterministic, no LLM)
 npm run typecheck    # tsc --noEmit
 
 npx tsx scripts/bench-graph.ts   # force-layout benchmark (synthetic graphs)
-
-# ── legacy v0 pipeline (dormant, see "Legacy scaffold" below) ──────────
-npm run ingest -- <session.jsonl>   # normalize a pi session JSONL
-npm run graph                       # ledger stats
 ```
 
 ## Environment (`.env.local`)
@@ -148,10 +144,6 @@ data/                           chats/ · graph/ · jobs/ — runtime state, git
 
 **The live graph.** Every completed turn folds the chat into append-only JSONL ledgers (`emitChat`: tree nodes/edges, quiz outcome events, taught events — idempotent, checkpointed, so partial sessions still deposit value). The home view derives node states from the ledgers and lays them out with forceAtlas2 (run-then-freeze — no idle simulation). At session start the derived graph is rendered into a compact markdown block appended to the teacher's instructions (`buildGraphContext`) — whole graph while small, hotspots + 1-hop neighborhood past 150 nodes.
 
-## Legacy scaffold (dormant)
-
-The pre-pivot v0 pipeline — `src/ledger.ts`, `src/cli.ts` (`npm run ingest` / `graph`), `src/extract/` (normalize ✅, extract/merge stubs), `src/schema.ts`, `src/derive.ts`, `src/queries/` — is kept compiling as reference for a future **retroactive bootstrap** over the old pi session JSONLs (`data/sessions/`, bootstrap input only). It writes to `data/legacy-graph/` and shares nothing with the live store (`data/graph/`, owned by `src/store/graph.ts` per the `contracts.ts` shapes). See `docs/architecture.md` for its design.
-
 ## Testing
 
 All deterministic, no LLM (models are injected as `MockLanguageModelV4` where an agent loop is under test):
diff --git a/config.ts b/config.ts
index f26882c..4e3d580 100644
--- a/config.ts
+++ b/config.ts
@@ -11,8 +11,6 @@ export const PATHS = {
 	data: path.join(ROOT, "data"),
 	/** Chat sessions (AI SDK UIMessage transcripts, one JSON file per chat). */
 	chats: path.join(ROOT, "data", "chats"),
-	/** Old pi session JSONLs — retroactive bootstrap input only. */
-	sessions: path.join(ROOT, "data", "sessions"),
 	graph: path.join(ROOT, "data", "graph"),
 } as const;
 
@@ -27,17 +25,3 @@ export const LEDGER_FILES = {
 	mappings: path.join(PATHS.graph, "mappings.jsonl"),
 	sessions: path.join(PATHS.graph, "sessions.jsonl"),
 } as const;
-
-/**
- * The legacy V0 scaffold (src/ledger.ts, src/cli.ts, src/extract/) writes
- * HERE instead — dormant pre-pivot reference code with its own line shapes
- * (src/schema.ts). Kept compiling for the future retroactive bootstrap,
- * which will target the contracts.ts shapes, not these.
- */
-export const LEGACY_LEDGER_FILES = {
-	nodes: path.join(PATHS.data, "legacy-graph", "nodes.jsonl"),
-	edges: path.join(PATHS.data, "legacy-graph", "edges.jsonl"),
-	events: path.join(PATHS.data, "legacy-graph", "events.jsonl"),
-	mappings: path.join(PATHS.data, "legacy-graph", "mappings.jsonl"),
-	sessions: path.join(PATHS.data, "legacy-graph", "sessions.jsonl"),
-} as const;
diff --git a/package.json b/package.json
index cbe1eb4..f2fa53d 100644
--- a/package.json
+++ b/package.json
@@ -8,9 +8,6 @@
 		"dev": "next dev",
 		"build": "next build",
 		"start": "next start",
-		"ingest": "tsx src/cli.ts ingest",
-		"graph": "tsx src/cli.ts graph",
-		"what-next": "tsx src/cli.ts what-next",
 		"test": "NODE_ENV=test tsx --test tests/*.test.ts tests/*.test.tsx",
 		"typecheck": "tsc --noEmit"
 	},
diff --git a/src/cli.ts b/src/cli.ts
deleted file mode 100644
index 69745b1..0000000
--- a/src/cli.ts
+++ /dev/null
@@ -1,69 +0,0 @@
-#!/usr/bin/env node
-/**
- * learning-harness CLI
- *
- *   ingest <file>     normalize a session JSONL and print the canonical document
- *                     (Stage 1 only — extractor/merger not yet implemented)
- *   graph             print graph/ledger stats
- *   what-next         (not yet implemented)
- *
- * The web app (Next.js + AI SDK): npm run dev
- */
-
-import * as fs from "node:fs";
-import { normalizeSession } from "./extract/normalize.ts";
-import { ledgers } from "./ledger.ts";
-import { deriveAll } from "./derive.ts";
-import { PATHS } from "../config.ts";
-
-async function main() {
-	const [command, ...rest] = process.argv.slice(2);
-
-	switch (command) {
-		case "ingest": {
-			const file = rest[0];
-			if (!file) {
-				console.error("Usage: ingest <session.jsonl>");
-				process.exit(1);
-			}
-			const doc = normalizeSession(file);
-			ledgers.appendSession(doc.session);
-			console.log(`Session: ${doc.session.id}`);
-			console.log(`Topic:   ${doc.session.topic}`);
-			console.log(`Entries: ${doc.entries.length}`);
-			const quizzes = doc.entries.filter((e) => e.kind === "quiz");
-			console.log(`Quizzes: ${quizzes.length}`);
-			// Full canonical document for inspection / later pipeline stages.
-			fs.mkdirSync(PATHS.graph, { recursive: true });
-			const out = `${PATHS.graph}/canonical-${doc.session.id.slice(0, 8)}.json`;
-			fs.writeFileSync(out, JSON.stringify(doc, null, "\t"), "utf-8");
-			console.log(`Canonical document written: ${out}`);
-			break;
-		}
-		case "graph": {
-			const nodes = ledgers.nodes();
-			const edges = ledgers.edges();
-			const events = ledgers.events();
-			const sessions = ledgers.sessions();
-			const derived = deriveAll();
-			console.log(`Sessions: ${sessions.length}`);
-			console.log(`Nodes:    ${nodes.length} (known: ${derived.filter((d) => d.known).length})`);
-			console.log(`Edges:    ${edges.length}`);
-			console.log(`Events:   ${events.length}`);
-			break;
-		}
-		case "what-next": {
-			console.error("Not implemented yet — needs extractor + merger first.");
-			process.exit(1);
-		}
-		default: {
-			console.log("Commands: ingest <file> | graph | what-next");
-			process.exit(command ? 1 : 0);
-		}
-	}
-}
-
-main().catch((err) => {
-	console.error(err);
-	process.exit(1);
-});
diff --git a/src/derive.ts b/src/derive.ts
deleted file mode 100644
index 1d3ece4..0000000
--- a/src/derive.ts
+++ /dev/null
@@ -1,37 +0,0 @@
-/**
- * Derived state — pure code, no LLM.
- * known (evidence) / understood (structure, aggregation semantics PARKED).
- * NOT YET IMPLEMENTED beyond the known-set.
- */
-
-import { ledgers } from "./ledger.ts";
-import { KNOWING_ORDER, type DerivedNodeState, type KnowingLevel } from "./schema.ts";
-
-/** Rubric → scalar. Deterministic code, never an LLM. */
-export function knowingScore(level: KnowingLevel): number {
-	return KNOWING_ORDER.indexOf(level) / (KNOWING_ORDER.length - 1);
-}
-
-/** Known set: nodes with direct evidence (taught, probe-correct, check-correct...). */
-export function knownNodeIds(): Set<string> {
-	const evidenced = new Set<string>();
-	for (const event of ledgers.events()) {
-		if (event.kind === "taught" || event.kind === "check-correct" || event.kind === "probe-correct" || event.kind === "recall-at-delay") {
-			evidenced.add(event.node);
-		}
-	}
-	return evidenced;
-}
-
-/** Full derived state. Understanding aggregation (weakest-link vs mean vs two-level)
- *  is PARKED pending real extracted data — see docs/architecture.md §7. */
-export function deriveAll(): DerivedNodeState[] {
-	const known = knownNodeIds();
-	return ledgers.nodes().map((node) => ({
-		node: node.id,
-		known: known.has(node.id),
-		knowing: 0,
-		understood: 0,
-		floating: false,
-	}));
-}
diff --git a/src/extract/extract.ts b/src/extract/extract.ts
deleted file mode 100644
index 4479b40..0000000
--- a/src/extract/extract.ts
+++ /dev/null
@@ -1,26 +0,0 @@
-/**
- * Stage 2 — Extract (one LLM pass over the canonical session document).
- * NOT YET IMPLEMENTED. Interface specified so the shape is fixed:
- *
- *   Input:  CanonicalSessionDocument
- *   Output: ExtractedSession (see schema.ts) — nodes, edges, attributed events,
- *           per-node knowing on the anchored ordinal rubric.
- *
- * Constraints:
- *   - One pass for nodes+edges+events+knowing (they are entangled).
- *   - Zero inference about knowledge beyond the evidence: it extracts facts,
- *     edges, and evidence — nothing the session doesn't show.
- *   - Knowing is mapped onto the anchored rubric (KnowingLevel), never a scalar.
- *   - Edges come primarily from the plan's mermaid DAG (already asserted by the
- *     teacher); only prose-articulated Connect-step edges need judgment.
- *
- * Followed by an audit pass (extract/audit.ts): a second LLM call verifying the
- * extraction JSON against the session for hallucination/misattribution.
- */
-
-import type { CanonicalSessionDocument } from "./normalize.ts";
-import type { ExtractedSession } from "../schema.ts";
-
-export async function extractSession(doc: CanonicalSessionDocument): Promise<ExtractedSession> {
-	throw new Error("Not implemented — Stage 2 (extractor LLM pass) is the next build step.");
-}
diff --git a/src/extract/merge.ts b/src/extract/merge.ts
deleted file mode 100644
index 3175af6..0000000
--- a/src/extract/merge.ts
+++ /dev/null
@@ -1,22 +0,0 @@
-/**
- * Stage 3 — Merge (deterministic code + LLM adjudication for node identity).
- * NOT YET IMPLEMENTED. Interface specified:
- *
- *   Input:  ExtractedSession (Stage 2 output) + canonical graph
- *   1. Embed canonical node statements (cached) → kNN candidates per incoming node.
- *   2. ONE LLM adjudication call per session: each pair →
- *        same    → alias + attach events to canonical node
- *        related → new node + proposed cross-session edge (the quiet superpower)
- *        unrelated → new node, no edge
- *   3. Apply deterministically; log every decision as a SessionMapping
- *      (reversible by design — wrong merges must be one-line fixes).
- *
- * Policy: fully automatic, conservative — prefer duplicates over wrong merges.
- * No domain filter on candidates (cross-domain merging is the point).
- */
-
-import type { ExtractedSession } from "../schema.ts";
-
-export async function mergeSession(extraction: ExtractedSession): Promise<void> {
-	throw new Error("Not implemented — Stage 3 (merger) comes after the extractor.");
-}
diff --git a/src/extract/normalize.ts b/src/extract/normalize.ts
deleted file mode 100644
index decd4d5..0000000
--- a/src/extract/normalize.ts
+++ /dev/null
@@ -1,217 +0,0 @@
-/**
- * Stage 1 of the extraction pipeline — DETERMINISTIC, no LLM.
- *
- * pi session JSONL → canonical session document.
- *
- * The quiz tool writes full structured details into the session JSONL
- * (question, options, correct/dontKnow, note, explanation), so quiz events are
- * read as gold-standard structured data, not parsed from prose.
- */
-
-import * as fs from "node:fs";
-import type {
-	EventKind,
-	Provenance,
-	SessionRecord,
-} from "../schema.ts";
-
-// ─── pi session JSONL entry types (subset we consume) ───────────────────────
-
-interface PiEntryBase {
-	type: string;
-	id: string;
-	parentId: string | null;
-	timestamp: string;
-}
-
-interface PiSessionHeader {
-	type: "session";
-	version: number;
-	id: string;
-	timestamp: string;
-	cwd: string;
-}
-
-interface PiMessageEntry extends PiEntryBase {
-	type: "message";
-	message: {
-		role: "user" | "assistant" | "toolResult" | string;
-		content?: unknown;
-		toolCallId?: string;
-		toolName?: string;
-		details?: unknown;
-		timestamp?: number;
-	};
-}
-
-// ─── Canonical session document ──────────────────────────────────────────────
-
-export interface CanonicalQuizEvent {
-	kind: "quiz";
-	entryId: string;
-	toolCallEntryId: string; // the assistant entry containing the toolCall
-	question: string;
-	context?: string;
-	options: Array<{ index: number; label: string }>;
-	answers: Array<{ index: number; label: string }>;
-	correctIndices: number[];
-	correct: boolean;
-	dontKnow: boolean;
-	note?: string;
-	explanation?: string;
-}
-
-export interface CanonicalAskEvent {
-	kind: "ask";
-	entryId: string;
-	toolCallEntryId: string;
-	question: string;
-	answers: Array<{ label: string; value: string }>;
-}
-
-export interface CanonicalTextEvent {
-	kind: "user" | "assistant";
-	entryId: string;
-	text: string;
-}
-
-export type CanonicalEntry = CanonicalQuizEvent | CanonicalAskEvent | CanonicalTextEvent;
-
-export interface CanonicalSessionDocument {
-	session: SessionRecord;
-	entries: CanonicalEntry[];
-}
-
-// ─── Parsing ─────────────────────────────────────────────────────────────────
-
-function textFromContent(content: unknown): string {
-	if (typeof content === "string") return content;
-	if (!Array.isArray(content)) return "";
-	return content
-		.filter((b): b is { type: "text"; text: string } => typeof b === "object" && b !== null && (b as { type: string }).type === "text")
-		.map((b) => b.text)
-		.join("\n");
-}
-
-interface QuizDetails {
-	status: string;
-	question: string;
-	mode: string;
-	answers: Array<{ index: number; label: string }>;
-	correctIndices: number[];
-	options?: Array<{ index: number; label: string }>;
-	correct?: boolean;
-	dontKnow?: boolean;
-	note?: string;
-	explanation?: string;
-}
-
-interface AskDetails {
-	status: string;
-	question: string;
-	mode: string;
-	answers?: Array<{ label: string; value: string }>;
-}
-
-export function normalizeSession(file: string): CanonicalSessionDocument {
-	const lines = fs.readFileSync(file, "utf-8").split("\n").filter((l) => l.trim().length > 0);
-	const parsed = lines.map((l) => JSON.parse(l));
-
-	const header = parsed[0] as PiSessionHeader;
-	if (header?.type !== "session") throw new Error(`${file}: not a pi session file (missing header)`);
-
-	const entries: CanonicalEntry[] = [];
-	const quizArgsByCallId = new Map<string, { entryId: string; question: string; context?: string }>();
-
-	for (const raw of parsed.slice(1)) {
-		const entry = raw as PiMessageEntry;
-		if (entry.type !== "message") continue;
-		const msg = entry.message;
-
-		if (msg.role === "user") {
-			const text = textFromContent(msg.content).trim();
-			if (text) entries.push({ kind: "user", entryId: entry.id, text });
-		}
-
-		if (msg.role === "assistant" && Array.isArray(msg.content)) {
-			// Collect assistant text (lesson prose — node articulations live here).
-			const text = textFromContent(msg.content).trim();
-			if (text) entries.push({ kind: "assistant", entryId: entry.id, text });
-			// Remember quiz/ask toolCall args (the question) keyed by call id.
-			for (const block of msg.content) {
-				if (typeof block === "object" && block !== null && (block as { type: string }).type === "toolCall") {
-					const call = block as { type: "toolCall"; id: string; name: string; arguments: Record<string, unknown> };
-					if (call.name === "quiz" || call.name === "ask_user_question") {
-						quizArgsByCallId.set(call.id, {
-							entryId: entry.id,
-							question: String(call.arguments.question ?? ""),
-							context: call.arguments.details ? String(call.arguments.details) : undefined,
-						});
-					}
-				}
-			}
-		}
-
-		if (msg.role === "toolResult" && (msg.toolName === "quiz" || msg.toolName === "ask_user_question")) {
-			const args = quizArgsByCallId.get(msg.toolCallId ?? "");
-			if (msg.toolName === "quiz") {
-				const d = msg.details as QuizDetails | undefined;
-				if (d && d.status === "answered") {
-					entries.push({
-						kind: "quiz",
-						entryId: entry.id,
-						toolCallEntryId: args?.entryId ?? entry.id,
-						question: d.question ?? args?.question ?? "",
-						context: args?.context,
-						options: d.options ?? [],
-						answers: d.answers ?? [],
-						correctIndices: d.correctIndices ?? [],
-						correct: d.correct ?? false,
-						dontKnow: d.dontKnow ?? false,
-						note: d.note,
-						explanation: d.explanation,
-					});
-				}
-			} else {
-				const d = msg.details as AskDetails | undefined;
-				if (d && d.status === "answered") {
-					entries.push({
-						kind: "ask",
-						entryId: entry.id,
-						toolCallEntryId: args?.entryId ?? entry.id,
-						question: d.question ?? args?.question ?? "",
-						answers: d.answers ?? [],
-					});
-				}
-			}
-		}
-	}
-
-	const firstUser = entries.find((e): e is CanonicalTextEvent => e.kind === "user");
-
-	return {
-		session: {
-			id: header.id,
-			startedAt: header.timestamp,
-			topic: firstUser ? firstUser.text.slice(0, 120) : "(no user message)",
-			file,
-		},
-		entries,
-	};
-}
-
-/** Coarse pre-plan / post-plan classification for quiz events (refined by the extractor LLM). */
-export function quizPhase(index: number, planIndex: number): "probe" | "check" {
-	return index < planIndex ? "probe" : "check";
-}
-
-/** Provisional event kind from a quiz outcome + phase (the extractor refines/attribution). */
-export function provisionalEventKind(quiz: CanonicalQuizEvent, phase: "probe" | "check"): EventKind {
-	if (quiz.dontKnow) return "dontKnow";
-	if (phase === "probe") return quiz.correct ? "probe-correct" : "probe-miss";
-	return quiz.correct ? "check-correct" : "check-incorrect";
-}
-
-export function provenanceOf(sessionId: string, entryId: string): Provenance {
-	return { session: sessionId, entryId };
-}
diff --git a/src/ledger.ts b/src/ledger.ts
deleted file mode 100644
index 7ca0106..0000000
--- a/src/ledger.ts
+++ /dev/null
@@ -1,68 +0,0 @@
-/**
- * Append-only JSONL ledgers. Same philosophy as the design: the ledgers are
- * the source of truth; everything else is derived and recomputable.
- */
-
-import * as fs from "node:fs";
-import * as path from "node:path";
-import { randomBytes } from "node:crypto";
-import { LEGACY_LEDGER_FILES as LEDGER_FILES } from "../config.ts";
-
-export function newId(prefix: string): string {
-	return `${prefix}_${randomBytes(5).toString("hex")}`;
-}
-
-export function append<T>(file: string, record: T): void {
-	fs.mkdirSync(path.dirname(file), { recursive: true });
-	fs.appendFileSync(file, JSON.stringify(record) + "\n", "utf-8");
-}
-
-export function readAll<T>(file: string): T[] {
-	if (!fs.existsSync(file)) return [];
-	const out: T[] = [];
-	for (const line of fs.readFileSync(file, "utf-8").split("\n")) {
-		const trimmed = line.trim();
-		if (trimmed.length > 0) out.push(JSON.parse(trimmed) as T);
-	}
-	return out;
-}
-
-// Typed helpers ───────────────────────────────────────────────────────────────
-
-import type {
-	GraphEdge,
-	GraphNode,
-	KnowledgeEvent,
-	SessionMapping,
-	SessionRecord,
-} from "./schema.ts";
-
-export const ledgers = {
-	appendSession(record: SessionRecord) {
-		// Session records are unique per id — skip if already ingested.
-		if (readAll<SessionRecord>(LEDGER_FILES.sessions).some((s) => s.id === record.id)) return false;
-		append(LEDGER_FILES.sessions, record);
-		return true;
-	},
-	sessions: () => readAll<SessionRecord>(LEDGER_FILES.sessions),
-
-	appendNode(node: GraphNode) {
-		append(LEDGER_FILES.nodes, node);
-	},
-	nodes: () => readAll<GraphNode>(LEDGER_FILES.nodes),
-
-	appendEdge(edge: GraphEdge) {
-		append(LEDGER_FILES.edges, edge);
-	},
-	edges: () => readAll<GraphEdge>(LEDGER_FILES.edges),
-
-	appendEvent(event: KnowledgeEvent) {
-		append(LEDGER_FILES.events, event);
-	},
-	events: () => readAll<KnowledgeEvent>(LEDGER_FILES.events),
-
-	appendMapping(mapping: SessionMapping) {
-		append(LEDGER_FILES.mappings, mapping);
-	},
-	mappings: () => readAll<SessionMapping>(LEDGER_FILES.mappings),
-};
diff --git a/src/queries/what-next.ts b/src/queries/what-next.ts
deleted file mode 100644
index 0f9ea97..0000000
--- a/src/queries/what-next.ts
+++ /dev/null
@@ -1,18 +0,0 @@
-/**
- * What-next queries: territory / repairs / conversions (+ unlock-value over
- * the expanded frontier). NOT YET IMPLEMENTED — needs the graph populated first.
- *
- * These run as pure traversals over the derived graph:
- *   territory    — frontier candidates ranked by work-to-ready (missing
- *                  requires-subtree mass), NOT fewest edges.
- *   repairs      — weak/shaky/misconceived nodes INSIDE the held region,
- *                  ranked by downstream load.
- *   conversions  — missing requires-roots that would flip known-but-floating
- *                  nodes into understood.
- *   unlock-value — over the lazily expanded frontier, discounted by depth in
- *                  generated territory; presented as ranked heuristic, never a number.
- */
-
-export async function whatNext(): Promise<void> {
-	throw new Error("Not implemented — needs a populated graph (extractor + merger first).");
-}
diff --git a/src/schema.ts b/src/schema.ts
deleted file mode 100644
index e011258..0000000
--- a/src/schema.ts
+++ /dev/null
@@ -1,170 +0,0 @@
-/**
- * Knowledge graph data model.
- *
- * Design invariants (see docs/architecture.md and the design session):
- *   1. Store the LEDGERS, derive the GRAPH. Events/edges/mappings are append-only
- *      evidence; node states and strengths are always recomputable from them.
- *   2. Nodes are propositions at ~one-reasoning-step grain.
- *   3. Edges carry NO scalars — only type (requires/supports) and provenance.
- *      All mass lives in nodes. "Load-bearing" is derived, never stored.
- *   4. known ≠ understood. Known = evidence property (from the event ledger).
- *      Understood = derived structural property (known + requires-subtree held).
- *   5. Candidates (frontier-generated nodes) are a separate state class;
- *      promotion only happens when a session touches them or the learner
- *      picks them as a goal — never automatically.
- *   6. Every event carries session + entryId → jump-to-point provenance.
- */
-
-// ─── Sessions ────────────────────────────────────────────────────────────────
-
-export interface SessionRecord {
-	/** pi session UUID (from the session JSONL header). */
-	id: string;
-	/** ISO timestamp from the header. */
-	startedAt: string;
-	/** Human topic label (first user message, or /name). */
-	topic: string;
-	/** Absolute path of the session JSONL. */
-	file: string;
-}
-
-// ─── Nodes ───────────────────────────────────────────────────────────────────
-
-export type NodeKind = "truth" | "misconception";
-export type NodeState = "known" | "not-held" | "candidate";
-
-export interface GraphNode {
-	/** Opaque stable id, e.g. "n_a1b2c3". */
-	id: string;
-	/** The proposition, one reasoning step of grain. */
-	statement: string;
-	kind: NodeKind;
-	/** Domain tag — metadata for visualization, NEVER a merge barrier. */
-	domain: string;
-	/** candidate = generated by frontier expansion, not yet evidenced. */
-	state: NodeState;
-	createdAt: number;
-}
-
-// ─── Edges ───────────────────────────────────────────────────────────────────
-
-export type EdgeType = "requires" | "supports";
-
-export interface GraphEdge {
-	id: string;
-	/** The dependency (e.g. "gradient" for gradient descent). */
-	from: string;
-	/** The dependent (e.g. "gradient descent"). */
-	to: string;
-	/**
-	 * requires  — hard: understanding the target requires holding this.
-	 * supports  — soft: the target is more anchored with it, holdable without it.
-	 */
-	type: EdgeType;
-	provenance: Provenance;
-}
-
-export interface Provenance {
-	session: string;
-	/** Entry id in the session JSONL — jump-to-point. */
-	entryId: string;
-}
-
-// ─── Events (append-only ledger — the source of truth) ──────────────────────
-
-export type EventKind =
-	| "probe-correct" // pre-plan quiz, answered correctly (floor evidence)
-	| "probe-miss" // pre-plan quiz, wrong answer (ceiling evidence)
-	| "dontKnow" // "I don't know" — genuine gap, not a guess
-	| "misconception-signaled" // specific wrong belief identified via distractor/note
-	| "taught" // node established in Phase 3
-	| "check-correct" // post-teach quiz-check, first try
-	| "check-incorrect" // post-teach quiz-check, missed
-	| "recall-at-delay"; // future: spaced repetition
-
-export interface EventEvidence {
-	quizQuestion: string;
-	/** What the learner selected (labels). */
-	answer: string[];
-	/** Free-text note typed with the answer — diagnostic gold. */
-	note?: string;
-}
-
-export interface KnowledgeEvent {
-	id: string;
-	node: string;
-	kind: EventKind;
-	session: string;
-	/** Entry id in the session JSONL → jump to the exact point where this happened. */
-	entryId: string;
-	timestamp: number;
-	evidence?: EventEvidence;
-}
-
-// ─── Mappings (merge decisions — reversible by design) ──────────────────────
-
-export interface SessionMapping {
-	/** Session-local node reference from the extraction JSON. */
-	sessionNodeRef: { session: string; localId: string };
-	canonicalNode: string;
-	decidedBy: "llm-adjudication";
-	confidence: number;
-	/** Mirror of the session-local statement, for auditability. */
-	sessionStatement: string;
-}
-
-// ─── Knowing assessment (anchored ordinal rubric — NEVER freehand scalars) ──
-
-export type KnowingLevel =
-	| "misconception" // actively holds a wrong version
-	| "absent" // dontKnow or wrong with no reasoning
-	| "shakily-known" // correct after a miss, or correct with a hedging note
-	| "known" // first-try correct
-	| "fluent"; // correct AND the note/reasoning shows the right model
-
-/** Ordinal index — deterministic code maps rubric → number, never an LLM. */
-export const KNOWING_ORDER: readonly KnowingLevel[] = [
-	"misconception",
-	"absent",
-	"shakily-known",
-	"known",
-	"fluent",
-];
-
-// ─── Extraction pipeline (per-session JSON, Stage 2 output) ─────────────────
-
-export interface ExtractedSession {
-	session: string;
-	nodes: Array<{
-		localId: string;
-		statement: string;
-		kind: NodeKind;
-		domain: string;
-	}>;
-	edges: Array<{
-		from: string; // localId
-		to: string; // localId
-		type: EdgeType;
-	}>;
-	events: Array<{
-		node: string; // localId
-		kind: EventKind;
-		entryId: string;
-		evidence?: EventEvidence;
-	}>;
-	knowing: Array<{
-		node: string; // localId
-		level: KnowingLevel;
-		justification: string;
-	}>;
-}
-
-// ─── Derived state (computed by code, never stored as primary data) ─────────
-
-export interface DerivedNodeState {
-	node: string;
-	known: boolean;
-	knowing: number; // 0..1, from rubric + evidence events
-	understood: number; // 0..1, recursive over requires-subtree (aggregation semantics PARKED)
-	floating: boolean; // known but not understood
-}