Fix Spring AI 2.0 conversationId cannot be null in chat memory
Spring AI 2.0 and 1.1.6 removed DEFAULT_CONVERSATION_ID, so chat memory calls fail with conversationId cannot be null. Reproduced and fixed with per-user IDs.
Ollama
Spring AI 2.0: ChatModel tool calls not executed, empty answer
After upgrading to Spring AI 2.0, @Tool methods passed to ChatModel.call() never run and the answer is empty. Reproduced on 2.0.2, with two fixes.