⚡ Introduce a new high-performing standalone chat API (#1200)

Closes #1154

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

- **New Features**
	- Added authentication functionality for user sessions in chat API.
- Introduced chat-related API endpoints for starting, previewing, and
continuing chat sessions, and streaming messages.
- Implemented WhatsApp API webhook handling for receiving and processing
messages.
- Added environment variable `NEXT_PUBLIC_CHAT_API_URL` for chat API URL
configuration.

- **Bug Fixes**
	- Adjusted file upload logic to correctly determine the API host.
	- Fixed message streaming URL in chat integration with OpenAI.

- **Documentation**
- Updated guides for creating blocks, local installation, self-hosting,
and deployment to use `bun` instead of `pnpm`.

- **Refactor**
	- Refactored chat API functionalities to use modular architecture.
- Simplified client log saving and session update functionalities by
using external functions.
	- Transitioned package management and workflow commands to use `bun`.

- **Chores**
- Switched to `bun` for package management in Dockerfiles and GitHub
workflows.
	- Added new Dockerfile for chat API service setup with Bun framework.
	- Updated `.prettierignore` and documentation with new commands.

- **Style**
	- No visible changes to end-users.

- **Tests**
	- No visible changes to end-users.

- **Revert**
	- No reverts in this release.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/embeds/js/src/features/blocks/inputs/fileUpload/components/FileUploadForm.tsx

@@ -73,7 +73,8 @@ export const FileUploadForm = (props: Props) => {
       })
     setIsUploading(true)
     const urls = await uploadFiles({
-      apiHost: props.context.apiHost ?? guessApiHost(),
+      apiHost:
+        props.context.apiHost ?? guessApiHost({ ignoreChatApiUrl: true }),
       files: [
         {
           file,
@@ -112,7 +113,8 @@ export const FileUploadForm = (props: Props) => {
       })
     setIsUploading(true)
     const urls = await uploadFiles({
-      apiHost: props.context.apiHost ?? guessApiHost(),
+      apiHost:
+        props.context.apiHost ?? guessApiHost({ ignoreChatApiUrl: true }),
       files: files.map((file) => ({
         file: file,
         input: {

packages/embeds/js/src/features/blocks/integrations/openai/streamChat.ts

@@ -25,16 +25,15 @@ export const streamChat =
       const apiHost = context.apiHost
 
       const res = await fetch(
-        `${
-          isNotEmpty(apiHost) ? apiHost : guessApiHost()
-        }/api/integrations/openai/streamer`,
+        `${isNotEmpty(apiHost) ? apiHost : guessApiHost()}/api/v1/sessions/${
+          context.sessionId
+        }/streamMessage`,
         {
           method: 'POST',
           headers: {
             'Content-Type': 'application/json',
           },
           body: JSON.stringify({
-            sessionId: context.sessionId,
             messages,
           }),
           signal: abortController.signal,