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/graph-tools.test.ts

@@ -138,7 +138,7 @@ describe("list_sessions", () => {
 			},
 		);
 		const tools = createProberTools({ ...baseCtx, chatStore, graphStore });
-		const out = (await tools.list_sessions!.execute!({}, { toolCallId: "tc" })) as string;
+		const out = (await tools.list_sessions!.execute!("tc", {})).details as string;
 		assert.match(out, /2 session\(s\) in the knowledge graph, most recent first:/);
 		// The chat: name, kind, born count, dates, id — the full resume.
 		assert.match(out, /First lesson \(chat, 2 propositions, born 2026-09-20T10:00:00.000Z, last active 2026-09-21T10:00:00.000Z\) — id: c1/);
@@ -151,7 +151,7 @@ describe("list_sessions", () => {
 	it("an empty graph gets an honest answer, not an empty string or a throw", async () => {
 		const { chatStore, graphStore } = fakeStores([]);
 		const tools = createProberTools({ ...baseCtx, chatStore, graphStore });
-		const out = (await tools.list_sessions!.execute!({}, { toolCallId: "tc" })) as string;
+		const out = (await tools.list_sessions!.execute!("tc", {})).details as string;
 		assert.equal(out, "The knowledge graph is empty — no session has contributed propositions yet.");
 	});
 });
@@ -172,7 +172,7 @@ describe("list_propositions", () => {
 			},
 		);
 		const tools = createProberTools({ ...baseCtx, chatStore, graphStore });
-		const out = (await tools.list_propositions!.execute!({ session: "c1" }, { toolCallId: "tc" })) as string;
+		const out = (await tools.list_propositions!.execute!("tc", { session: "c1" })).details as string;
 		assert.match(out, /2 proposition\(s\) born in this session:/);
 		assert.match(out, /- Water cycle — solid \(as of 2026-09-22T12:00:00.000Z\)/);
 		assert.match(out, /- Evaporation — not yet engaged \(as of 2026-09-21T12:00:00.000Z\)/);
@@ -186,7 +186,7 @@ describe("list_propositions", () => {
 			events: [],
 		});
 		const tools = createProberTools({ ...baseCtx, chatStore, graphStore });
-		const out = (await tools.list_propositions!.execute!({ session: "c1" }, { toolCallId: "tc" })) as string;
+		const out = (await tools.list_propositions!.execute!("tc", { session: "c1" })).details as string;
 		assert.match(out, /- Water cycle — never evaluated/);
 		assert.ok(!out.includes("(as of"));
 	});
@@ -194,7 +194,7 @@ describe("list_propositions", () => {
 	it("an unknown session id — honest redirect, not a throw", async () => {
 		const { chatStore, graphStore } = fakeStores([node("n1", "Water cycle", [pt("c1")])]);
 		const tools = createProberTools({ ...baseCtx, chatStore, graphStore });
-		const out = (await tools.list_propositions!.execute!({ session: "no-such" }, { toolCallId: "tc" })) as string;
+		const out = (await tools.list_propositions!.execute!("tc", { session: "no-such" })).details as string;
 		assert.equal(out, 'No propositions born in session "no-such". Call list_sessions for the current ids.');
 	});
 });