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/tools/probe.ts

@@ -1,5 +1,6 @@
-import { lhTool, type LhTool } from "../lh-tool.ts";
-import { probeDoneInputSchema, type ProbeDoneInput, type ProbeDoneResult } from "../../core/contracts.ts";
+import type { AgentTool } from "@earendil-works/pi-agent-core";
+import { serverExecute } from "../tool-execute.ts";
+import { probeDoneInputSchema, type ProbeDoneResult } from "../../core/contracts.ts";
 import type { UIMessage } from "ai";
 import { findPendingToolCall } from "../../core/pending.ts";
 import type { ChatStore } from "../../core/ports.ts";
@@ -43,10 +44,11 @@ function probeConcluded(messages: UIMessage[]): boolean {
  * The first probe_done in the transcript is also the construction seam:
  * from that message on, every request builds the TEACHER agent.
  */
-export function probeDoneTool(ctx: ProbeDoneContext): Record<string, LhTool<any, any>> {
+export function probeDoneTool(ctx: ProbeDoneContext): Record<string, AgentTool<any>> {
 	return {
-		probe_done: lhTool({
+		probe_done: {
 			name: "probe_done",
+			label: "probe_done",
 			description:
 				"Conclude the probing phase and hand off to the teaching phase. Call this ONCE, when the probe is " +
 				"complete: every strand the lesson depends on is bracketed (a floor he reliably gets right AND a " +
@@ -57,8 +59,8 @@ export function probeDoneTool(ctx: ProbeDoneContext): Record<string, LhTool<any,
 				"the probe is already concluded. After it succeeds, say your closing sentence and end your turn.",
 			// The core-owned schema (contracts/probe.ts) — the SAME schema the UI
 			// parse seam (tool-parts.ts) runs, so boundary-valid ⇔ consumer-parseable.
-			schema: probeDoneInputSchema,
-			execute: async (input): Promise<ProbeDoneResult> => {
+			parameters: probeDoneInputSchema,
+			execute: serverExecute("probe_done", probeDoneInputSchema, async (input): Promise<ProbeDoneResult> => {
 				const record = ctx.chatStore.getChat(ctx.chatId);
 				if (!record) return { ok: false, error: `Chat not found: ${ctx.chatId}` };
 
@@ -82,7 +84,7 @@ export function probeDoneTool(ctx: ProbeDoneContext): Record<string, LhTool<any,
 					// assessment anyway; the wake is an optimization, not a gate.
 				}
 				return { ok: true, assessment: input.assessment };
-			},
-		}),
+			}),
+		},
 	};
 }