fix(ai): Fix OpenAI Responses provider multi-turn conversation support

- Added contentSignature tracking for assistant messages
- Fixed message format in convertToResponsesFormat (output_text instead of input_text)
- Properly preserve message IDs for multi-turn conversations
- Added proper ResponseOutputMessage type satisfaction
- Updated tests to cover more providers and multi-turn scenarios

packages/agent/package-lock.json

@@ -1,12 +1,12 @@
 {
 	"name": "@mariozechner/pi-agent",
-	"version": "0.5.12",
+	"version": "0.5.13",
 	"lockfileVersion": 3,
 	"requires": true,
 	"packages": {
 		"": {
 			"name": "@mariozechner/pi-agent",
-			"version": "0.5.12",
+			"version": "0.5.13",
 			"license": "MIT",
 			"dependencies": {
 				"@mariozechner/tui": "^0.1.1",