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/stdout-cleanliness.test.ts

@@ -60,6 +60,7 @@ async function runCli(args: string[]): Promise<{ stdout: string; stderr: string;
 			env: {
 				...process.env,
 				[ENV_AGENT_DIR]: agentDir,
+				TSX_TSCONFIG_PATH: resolve(__dirname, "../../../tsconfig.json"),
 			},
 			stdio: ["ignore", "pipe", "pipe"],
 		});