feat: implement create-chat-conversation function with OpenAI integration and Supabase support

- Added CORS handling for the create-chat-conversation function.
- Implemented health check endpoint for the function.
- Created endpoints for managing conversations and messages with OpenAI.
- Added error handling and response formatting for better API usability.
- Introduced utility functions for environment variable management and Supabase client creation.
- Enhanced schema handling for structured responses from OpenAI.
- Implemented conversation archiving and retrieval logic.

supabase/functions/create-chat-conversation/lib/errors.ts

@@ -0,0 +1,31 @@
+export class HttpError extends Error {
+  status: number;
+  code: string;
+  details?: unknown;
+
+  constructor(
+    status: number,
+    code: string,
+    message: string,
+    details?: unknown,
+  ) {
+    super(message);
+    this.status = status;
+    this.code = code;
+    this.details = details;
+  }
+}
+
+export function jsonResponse(
+  body: unknown,
+  status = 200,
+  headers: HeadersInit = {},
+) {
+  return new Response(JSON.stringify(body), {
+    status,
+    headers: {
+      "content-type": "application/json; charset=utf-8",
+      ...headers,
+    },
+  });
+}