feat(ai,agent,coding-agent): validate tool arguments with pi-schema, drop TypeBox

pi-schema: opt-in coercion, compile(schema, { coerce: true }) with coerce() and
parse(), the superset of TypeBox's Value.Convert rules and pi-ai's old coercion;
unresolvedRefs option; url and json-pointer-uri-fragment formats.
pi-ai: Tool takes any JSON Schema; validation through pi-schema; Type, Static
and TSchema are no longer exported (breaking). pi-agent-core and pi-durable:
tools on pi-schema, no TypeBox dependency. Coding agent: extensions keep Type,
Static, TSchema and StringEnum through an extension view of pi-ai; built-in
tools stay on TypeBox.

packages/coding-agent/install-lock/package-lock.json

@@ -391,7 +391,7 @@
 			"license": "MIT",
 			"dependencies": {
 				"@earendil-works/pi-ai": "1.4.0",
-				"typebox": "1.3.27"
+				"@earendil-works/pi-schema": "1.4.0"
 			},
 			"engines": {
 				"node": ">=22.19.0"
@@ -404,14 +404,14 @@
 			"dependencies": {
 				"@anthropic-ai/sdk": "0.129.0",
 				"@aws-sdk/client-bedrock-runtime": "3.1127.0",
+				"@earendil-works/pi-schema": "1.4.0",
 				"@earendil-works/pi-telemetry": "1.4.0",
 				"@google/genai": "2.21.0",
 				"@smithy/node-http-handler": "4.12.1",
 				"http-proxy-agent": "9.1.0",
 				"https-proxy-agent": "9.1.0",
 				"openai": "7.19.0",
-				"partial-json": "0.1.7",
-				"typebox": "1.3.27"
+				"partial-json": "0.1.7"
 			},
 			"bin": {
 				"pi-ai": "dist/cli.js"
@@ -537,6 +537,14 @@
 				"node": ">=22.19.0"
 			}
 		},
+		"node_modules/@earendil-works/pi-schema": {
+			"version": "1.4.0",
+			"resolved": "https://registry.npmjs.org/@earendil-works/pi-schema/-/pi-schema-1.4.0.tgz",
+			"license": "MIT",
+			"engines": {
+				"node": ">=22.19.0"
+			}
+		},
 		"node_modules/@earendil-works/pi-telemetry": {
 			"version": "1.4.0",
 			"resolved": "https://registry.npmjs.org/@earendil-works/pi-telemetry/-/pi-telemetry-1.4.0.tgz",