Wave A: pi-native tool layer — delete LhTool/toPiTool, TypeBox everywhere, terminate on questions

- src/agent/lh-tool.ts deleted: the zod-wrapped LhTool + toPiTool bridge
  (z.toJSONSchema per call, clientQuestion flag, hand-rolled result mapping)
  is gone. Tools are pi-agent-core native AgentTools now.
- New src/agent/tool-execute.ts owns what the wrapper added: the abort guard
  (runWithAbortGuard: run signal + 30s per-call timeout + 250ms grace,
  'Operation aborted' / timeout wording preserved), ToolInputError (the
  retryable '- problem at path' format), result mapping (string verbatim /
  object JSON / image parts, details rides the record's tool part output),
  and questionResult() — placeholder + terminate:true (owner Option A:
  belt of terminate + slim makeQuestionStopper with the clean-question
  rule; maxTurns deleted from the teaching turn entirely per owner).
- All 11 tool files + tools.ts registries converted to TypeBox parameters
  (typebox@1.3.7, pinned to pi-agent-core's copy). zod refinements
  (quizInputProblems, askOptionProblems, live-nodeId) moved from schemas
  into execute — the model sees the same retryable error shape.
- question-core + contracts/probe TypeBox-authored (single source shared
  with the UI); tool-parts parse seam runs the boundary's full chain
  (Convert → Check → Clean → refinement), fixing the live-smoke lockout:
  pi's boundary Value.Converts correctAnswer: 17 → '17' but the record
  keeps raw args, so a parse without Convert rejected a posed quiz
  (invisible pending question, turn ended). Pinned with the real smoke
  emission shape.
- Subagents converted: demo-builder/researcher AgentTool-native,
  visual-maker/pdf-reader declaration-only pi-ai Tools with local execute
  fns, extraction submit schemas re-authored in TypeBox (owner option 2:
  zod defaults → Type.Optional + fill at the submit seam).
- Accepted delta, flagged: TypeBox-native schemas skip pi's JSON-Schema
  primitive coercion fast path... (boundary still Value.Converts), and
  prober-quiz unknown keys ride through (Value.Clean strips at display).
- Tests: 988 passing (was 967 at the recon baseline); tool-abort and
  read-tool rewritten against the native seams; question-core/question-
  tools/tool-parts/demos/web-search/graph-tools/plan-tree/probe-done/
  tool-toggles converted to Value.Check/execute pins.

Live smoke (PORT=3004, real model): native ls turn streams end-to-end; a
real quiz pose (first attempt missing correctAnswer → tool-input-error →
model retry → posed) terminates the turn cleanly and persists pending.

tests/demos.test.tsx

@@ -28,6 +28,7 @@ import assert from "node:assert/strict";
 import * as fs from "node:fs";
 import * as path from "node:path";
 import { after, describe, it } from "node:test";
+import { Value } from "typebox/value";
 import { createFauxCore, fauxAssistantMessage, fauxToolCall, type FauxResponseStep } from "@earendil-works/pi-ai";
 import { renderToStaticMarkup } from "react-dom/server";
 import { PATHS } from "../config.ts";
@@ -845,13 +846,13 @@ describe("tool + renderer registry wiring", () => {
 		for (const name of ["demo", "visual", "research", "pdf"] as const) {
 			assert.equal(typeof (tools[name] as { execute?: unknown }).execute, "function", `${name} executes server-side — fire-and-forget ack per THE ASYNC PROTOCOL`);
 		}
-		assert.equal(demoInputSchema.safeParse({ title: "T", brief: "b" }).success, true);
-		assert.equal(demoInputSchema.safeParse({ brief: "b" }).success, false, "demo requires a title");
-		assert.equal(visualInputSchema.safeParse({ brief: "b" }).success, true);
-		assert.equal(visualInputSchema.safeParse({}).success, false, "visual requires a brief");
-		assert.equal(pdfInputSchema.safeParse({ path: "/tmp/doc.pdf", question: "q" }).success, true);
-		assert.equal(pdfInputSchema.safeParse({ question: "q" }).success, false, "pdf requires a path");
-		assert.equal(pdfInputSchema.safeParse({ path: "/tmp/doc.pdf" }).success, false, "pdf requires a question");
+		assert.equal(Value.Check(demoInputSchema, { title: "T", brief: "b" }), true);
+		assert.equal(Value.Check(demoInputSchema, { brief: "b" }), false, "demo requires a title");
+		assert.equal(Value.Check(visualInputSchema, { brief: "b" }), true);
+		assert.equal(Value.Check(visualInputSchema, {}), false, "visual requires a brief");
+		assert.equal(Value.Check(pdfInputSchema, { path: "/tmp/doc.pdf", question: "q" }), true);
+		assert.equal(Value.Check(pdfInputSchema, { question: "q" }), false, "pdf requires a path");
+		assert.equal(Value.Check(pdfInputSchema, { path: "/tmp/doc.pdf" }), false, "pdf requires a question");
 	});
 
 	it("the artifact renderer registry maps demo/visual to the W6 cards", () => {