Chat persistence

[urso]

With this change we store the chat and message history in postgres.

The Chat UI supports creation and deletion of chats. Chats also have a title. The title of the active chat can be modified by clicking on the title in the chat header.
The UI will not send all messages anymore, but only the most recent message. We fetch the chat history from the chats memory.

The change introduces a chat memory in lib/ai/memory.ts

The chats are stores in the new chats table. A chat is associated with a procject and can have an optional connection to act upon.

The chat messages are stored in the messages table.

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Name	Status	Preview	Updated (UTC)
agent	✅ Ready (Inspect)	Visit Preview	Mar 15, 2025 10:53pm

Pull Request Overview

This PR introduces chat persistence by storing chat and message history in PostgreSQL while updating both the backend and UI components to support chat creation, deletion, and title editing. Key changes include the addition of a new chat memory module in lib/ai/memory.ts, enhancements to the chat UI components (ChatsUI, ChatSidebar, and MessageCard), and updates to API routes and database schema changes.

Reviewed Changes

Copilot reviewed 13 out of 13 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
lib/ai/memory.ts	Introduces a Memory class for managing chats and a ChatMemory class for handling chat messages.
components/chats/chats-ui.tsx	Updates UI components to load chats from the database, handle chat creation/deletion, and support title editing.
components/chats/message-card.tsx	Refactors message rendering with a dedicated MarkdownRenderer and ThinkingIndicator.
lib/db/chats.ts & schema.ts	Implements new database interactions and schema changes for chats and messages.
app/api/chat/route.ts	Modifies the chat API route to integrate chat history and persist assistant responses.
components/chats/actions.ts	Adds actions for creating, updating, and deleting chats using the new Memory classes.
components/chats/chat-sidebar.tsx	Enhances the sidebar with a delete button and displays chat metadata.
lib/db/relations.ts & projects/[project]/chats/page.tsx	Updates relational mappings and integrates the new projectId parameter into the UI.

Comments suppressed due to low confidence (2)

apps/dbagent/src/app/api/chat/route.ts:39

• Ensure that chatId is validated (e.g. not null or undefined) before constructing a new ChatMemory instance to avoid potential runtime errors when processing the request.

const memory = new ChatMemory(chatId);

apps/dbagent/src/components/chats/chat-sidebar.tsx:47

• Consider adding an aria-label to the delete button (e.g. aria-label="Delete chat") to improve accessibility and clarify the button's purpose for assistive technologies.

<Button ...>{"×"}</Button>