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.

src/agent/subagents/researcher.ts

@@ -2,7 +2,6 @@ import type { AgentTool } from "@earendil-works/pi-agent-core";
 import type { Usage } from "@earendil-works/pi-ai";
 import { createWebTools } from "../tools/web.ts";
 import type { SearchProvider } from "../../core/search.ts";
-import { toPiTools } from "../lh-tool.ts";
 import type { PiEngine } from "../models.ts";
 import { runSubagent } from "./pi-run.ts";
 
@@ -80,7 +79,7 @@ export interface ResearcherRunOptions {
  * the loop scripted.
  */
 export async function runResearcherAgent(prompt: string, opts: ResearcherRunOptions = {}): Promise<string> {
-	const { text } = await runSubagent(toPiTools(createWebTools(opts.search ?? (() => null))) as AgentTool<any, any>[], {
+	const { text } = await runSubagent(Object.values(createWebTools(opts.search ?? (() => null))), {
 		role: "researcher",
 		prompt,
 		engine: opts.engine,