Patch Changes

• #1149 19c4fcf Thanks @corners99! - fix: use input instead of args for tool-call parts in message conversion

  When converting CopilotKit assistant messages with tool calls to VoltAgent format,
  the adapter was setting args on tool-call parts. The AI SDK's ToolCallPart
  interface expects input, causing the Anthropic provider to send undefined as
  the tool_use input — rejected by the API with:

  "messages.N.content.N.tool_use.input: Input should be a valid dictionary"