fix(typebox): migrate to v1 with extension compat (#3474)

* fix(typebox): migrate to v1 with extension compat

Replace AJV-based validation with TypeBox-native validation, keep legacy extension imports working (including @sinclair/typebox/compiler), and restore coercion for serialized/plain JSON schemas.

This change closes #3112.

* fix(typebox): use canonical imports and harden coercion

Switch first-party code to canonical typebox imports while retaining legacy extension aliases in the loader.

Remove obsolete runtime codegen guards, expand serialized JSON-schema coercion coverage, and update related tests and fixtures.

Fixes #3112.

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Co-authored-by: Mario Zechner <badlogicgames@gmail.com>

packages/coding-agent/test/agent-session-dynamic-tools.test.ts

@@ -2,7 +2,7 @@ import { existsSync, mkdirSync, rmSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
 import { getModel } from "@mariozechner/pi-ai";
-import { Type } from "@sinclair/typebox";
+import { Type } from "typebox";
 import { afterEach, beforeEach, describe, expect, it } from "vitest";
 import { DefaultResourceLoader } from "../src/core/resource-loader.js";
 import { createAgentSession } from "../src/core/sdk.js";