Add live search panel with debounced Himalaya search and help modal

src/mail/screens/__init__.py

@@ -4,6 +4,7 @@ from .OpenMessage import OpenMessageScreen
 from .DocumentViewer import DocumentViewerScreen
 from .LinkPanel import LinkPanel, LinkItem, extract_links_from_content
 from .ConfirmDialog import ConfirmDialog
+from .SearchPanel import SearchPanel, SearchHelpModal
 
 __all__ = [
     "CreateTaskScreen",
@@ -13,4 +14,6 @@ __all__ = [
     "LinkItem",
     "extract_links_from_content",
     "ConfirmDialog",
+    "SearchPanel",
+    "SearchHelpModal",
 ]