Refactor transcript fetching and processing scripts

- Introduced a new function `fetchTranscriptContent` to handle fetching transcripts with optional authentication.
- Enhanced error handling and logging for transcript fetching.
- Updated the `parseTranscriptToMessages` function to improve message parsing logic.
- Replaced the old session processing logic with a new approach that utilizes `SessionImport` records.
- Removed obsolete scripts related to manual triggers and whitespace fixing.
- Updated the server initialization to remove direct server handling, transitioning to a more modular approach.
- Improved overall code structure and readability across various scripts.

lib/types.ts

@@ -38,7 +38,7 @@ export interface User {
 export interface Message {
   id: string;
   sessionId: string;
-  timestamp: Date;
+  timestamp: Date | null;
   role: string; // "User", "Assistant", "System", etc.
   content: string;
   order: number; // Order within the conversation (0, 1, 2, ...)