feat: support memory import and export (#1521)

* feat: support memory import and export

* fix(memory): address review feedback

* style: format memory settings page

---------

Co-authored-by: Willem Jiang <willem.jiang@gmail.com>

backend/tests/test_memory_updater.py

@@ -7,6 +7,7 @@ from deerflow.agents.memory.updater import (
     clear_memory_data,
     create_memory_fact,
     delete_memory_fact,
+    import_memory_data,
     update_memory_fact,
 )
 from deerflow.config.memory_config import MemoryConfig
@@ -233,6 +234,31 @@ def test_delete_memory_fact_raises_for_unknown_id() -> None:
             raise AssertionError("Expected KeyError for missing fact id")
 
 
+def test_import_memory_data_saves_and_returns_imported_memory() -> None:
+    imported_memory = _make_memory(
+        facts=[
+            {
+                "id": "fact_import",
+                "content": "User works on DeerFlow.",
+                "category": "context",
+                "confidence": 0.87,
+                "createdAt": "2026-03-20T00:00:00Z",
+                "source": "manual",
+            }
+        ]
+    )
+    mock_storage = MagicMock()
+    mock_storage.save.return_value = True
+    mock_storage.load.return_value = imported_memory
+
+    with patch("deerflow.agents.memory.updater.get_memory_storage", return_value=mock_storage):
+        result = import_memory_data(imported_memory)
+
+    mock_storage.save.assert_called_once_with(imported_memory, None)
+    mock_storage.load.assert_called_once_with(None)
+    assert result == imported_memory
+
+
 def test_update_memory_fact_updates_only_matching_fact() -> None:
     current_memory = _make_memory(
         facts=[
@@ -349,7 +375,7 @@ def test_update_memory_fact_rejects_invalid_confidence() -> None:
 
 
 # ---------------------------------------------------------------------------
-# _extract_text — LLM response content normalization
+# _extract_text - LLM response content normalization
 # ---------------------------------------------------------------------------
 
 
@@ -409,7 +435,7 @@ class TestExtractText:
 
 
 # ---------------------------------------------------------------------------
-# format_conversation_for_update — handles mixed list content
+# format_conversation_for_update - handles mixed list content
 # ---------------------------------------------------------------------------
 
 
@@ -439,7 +465,7 @@ class TestFormatConversationForUpdate:
 
 
 # ---------------------------------------------------------------------------
-# update_memory — structured LLM response handling
+# update_memory - structured LLM response handling
 # ---------------------------------------------------------------------------