feat: Add Playbook Manager, Saved Searches, and Timeline View components

- Implemented PlaybookManager for creating and managing investigation playbooks with templates.
- Added SavedSearches component for managing bookmarked queries and recurring scans.
- Introduced TimelineView for visualizing forensic event timelines with zoomable charts.
- Enhanced backend processing with auto-queued jobs for dataset uploads and improved database concurrency.
- Updated frontend components for better user experience and performance optimizations.
- Documented changes in update log for future reference.

frontend/nginx.conf

@@ -16,6 +16,12 @@ server {
         proxy_set_header   X-Forwarded-For   $proxy_add_x_forwarded_for;
         proxy_set_header   X-Forwarded-Proto $scheme;
         proxy_read_timeout 300s;
+
+        # SSE streaming support for agent assist
+        proxy_buffering    off;
+        proxy_cache        off;
+        proxy_set_header   Connection '';
+        chunked_transfer_encoding off;
     }
 
     # SPA fallback  serve index.html for all non-file routes