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.

_aup_keywords_scope_and_missing.py

@@ -0,0 +1,57 @@
+from pathlib import Path
+p=Path(r'd:/Projects/Dev/ThreatHunt/backend/app/api/routes/keywords.py')
+t=p.read_text(encoding='utf-8')
+
+# add fast guard against unscoped global dataset scans
+insert_after='''async def run_scan(body: ScanRequest, db: AsyncSession = Depends(get_db)):\n    scanner = KeywordScanner(db)\n\n'''
+if insert_after not in t:
+    raise SystemExit('run_scan header block not found')
+if 'Select at least one dataset' not in t:
+    guard='''    if not body.dataset_ids and not body.scan_hunts and not body.scan_annotations and not body.scan_messages:\n        raise HTTPException(400, "Select at least one dataset or enable additional sources (hunts/annotations/messages)")\n\n'''
+    t=t.replace(insert_after, insert_after+guard)
+
+old='''        if missing:
+            missing_entries: list[dict] = []
+            for dataset_id in missing:
+                partial = await scanner.scan(dataset_ids=[dataset_id], theme_ids=body.theme_ids)
+                keyword_scan_cache.put(dataset_id, partial)
+                missing_entries.append({"result": partial, "built_at": None})
+
+            merged = _merge_cached_results(
+                cached_entries + missing_entries,
+                allowed_theme_names if body.theme_ids else None,
+            )
+            return {
+                "total_hits": merged["total_hits"],
+                "hits": merged["hits"],
+                "themes_scanned": len(themes),
+                "keywords_scanned": keywords_scanned,
+                "rows_scanned": merged["rows_scanned"],
+                "cache_used": len(cached_entries) > 0,
+                "cache_status": "partial" if cached_entries else "miss",
+                "cached_at": merged["cached_at"],
+            }
+'''
+new='''        if missing:
+            partial = await scanner.scan(dataset_ids=missing, theme_ids=body.theme_ids)
+            merged = _merge_cached_results(
+                cached_entries + [{"result": partial, "built_at": None}],
+                allowed_theme_names if body.theme_ids else None,
+            )
+            return {
+                "total_hits": merged["total_hits"],
+                "hits": merged["hits"],
+                "themes_scanned": len(themes),
+                "keywords_scanned": keywords_scanned,
+                "rows_scanned": merged["rows_scanned"],
+                "cache_used": len(cached_entries) > 0,
+                "cache_status": "partial" if cached_entries else "miss",
+                "cached_at": merged["cached_at"],
+            }
+'''
+if old not in t:
+    raise SystemExit('partial-cache missing block not found')
+t=t.replace(old,new)
+
+p.write_text(t,encoding='utf-8')
+print('hardened keywords scan scope + optimized missing-cache path')