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.

_patch_inventory_stats.py

@@ -0,0 +1,36 @@
+from pathlib import Path
+p=Path(r'd:/Projects/Dev/ThreatHunt/backend/app/services/host_inventory.py')
+t=p.read_text(encoding='utf-8')
+old='''    return {
+        "hosts": host_list,
+        "connections": conn_list,
+        "stats": {
+            "total_hosts": len(host_list),
+            "total_datasets_scanned": len(all_datasets),
+            "datasets_with_hosts": ds_with_hosts,
+            "total_rows_scanned": total_rows,
+            "hosts_with_ips": sum(1 for h in host_list if h['ips']),
+            "hosts_with_users": sum(1 for h in host_list if h['users']),
+        },
+    }
+'''
+new='''    return {
+        "hosts": host_list,
+        "connections": conn_list,
+        "stats": {
+            "total_hosts": len(host_list),
+            "total_datasets_scanned": len(all_datasets),
+            "datasets_with_hosts": ds_with_hosts,
+            "total_rows_scanned": total_rows,
+            "hosts_with_ips": sum(1 for h in host_list if h['ips']),
+            "hosts_with_users": sum(1 for h in host_list if h['users']),
+            "row_budget_per_dataset": settings.NETWORK_INVENTORY_MAX_ROWS_PER_DATASET,
+            "sampled_mode": settings.NETWORK_INVENTORY_MAX_ROWS_PER_DATASET > 0,
+        },
+    }
+'''
+if old not in t:
+    raise SystemExit('return block not found')
+t=t.replace(old,new)
+p.write_text(t,encoding='utf-8')
+print('patched inventory stats metadata')