Opdater GEMINI.md med teknisk dokumentation af 'Self-Healing Sessions'

GEMINI.md

@@ -17,7 +17,8 @@ A production-ready Python utility for robust synchronization of SharePoint Onlin
 2.  **Reliability:** Includes a custom `retry_request` decorator for Exponential Backoff, handling throttling (429) and transient network errors.
 3.  **Concurrency:** Multi-threaded architecture (5 workers) for simultaneous scanning and downloading.
 4.  **Pagination:** Full support for OData pagination, ensuring complete folder traversal regardless of item count.
-5.  **Logging & Audit:** Integrated Python `logging` to `sharepoint_download.log` and structured CSV reports for error auditing.
+5.  **Self-Healing Sessions:** Automatically detects and resolves 401 Unauthorized errors by refreshing both expiring Microsoft Graph Download URLs and MSAL Access Tokens mid-process.
+6.  **Logging & Audit:** Integrated Python `logging` to `sharepoint_download.log` and structured CSV reports for error auditing.
 
 ## Building and Running
 
@@ -30,7 +31,8 @@ A production-ready Python utility for robust synchronization of SharePoint Onlin
 
 ## Development Conventions
 
-*   **Error Handling:** Always use the `safe_get` (retry-wrapped) method for Graph API calls.
+*   **Error Handling:** Always use the `safe_get` (retry-wrapped) method for Graph API calls. For item-specific operations, use `get_fresh_download_url` to handle token/URL expiry.
+*   **Authentication:** Use `get_headers(app, force_refresh=True)` when a 401 error is encountered from Graph API to ensure session continuity.
 *   **Thread Safety:** Use `report_lock` when updating the shared error list from worker threads.
 *   **Logging:** Prefer `logger.info()` or `logger.error()` over `print()` to ensure persistence in `sharepoint_download.log`.
 *   **Integrity:** Always verify file integrity using `size` and `quickXorHash` where available.