feat(agents): Add tool input attributes to conversation details endpoint

Add gen_ai.tool.call.arguments and gen_ai.tool.input to the
AI_CONVERSATION_ATTRIBUTES so tool input preview is available
in the conversation drawer.

https://claude.ai/code/session_0113Szysfr5Bf4ZQZ59nkxgJ

Author: claude

src/sentry/api/endpoints/organization_ai_conversation_details.py

@@ -46,6 +46,8 @@
     "gen_ai.response.object",
     "gen_ai.response.text",
     "gen_ai.tool.name",
+    "gen_ai.tool.call.arguments",
+    "gen_ai.tool.input",
     "gen_ai.usage.total_tokens",
     "gen_ai.request.model",
     "gen_ai.response.model",