refactor(tests): reorganize tests into unittest/ and e2e/ directories

- Move all unit tests from tests/ to tests/unittest/
- Add tests/e2e/ directory for end-to-end tests
- Update conftest.py for new test structure
- Add new tests for auth dependencies, policies, route injection
- Add new tests for run callbacks, create store, execution artifacts
- Remove obsolete tests for deleted persistence layer

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/tests/unittest/test_migration_user_isolation.py

@@ -0,0 +1,116 @@
+"""Tests for per-user data migration."""
+import json
+import pytest
+from pathlib import Path
+
+from deerflow.config.paths import Paths
+
+
+@pytest.fixture
+def base_dir(tmp_path: Path) -> Path:
+    return tmp_path
+
+
+@pytest.fixture
+def paths(base_dir: Path) -> Paths:
+    return Paths(base_dir)
+
+
+class TestMigrateThreadDirs:
+    def test_moves_thread_to_user_dir(self, base_dir: Path, paths: Paths):
+        legacy = base_dir / "threads" / "t1" / "user-data" / "workspace"
+        legacy.mkdir(parents=True)
+        (legacy / "file.txt").write_text("hello")
+
+        from scripts.migrate_user_isolation import migrate_thread_dirs
+        migrate_thread_dirs(paths, thread_owner_map={"t1": "alice"})
+
+        expected = base_dir / "users" / "alice" / "threads" / "t1" / "user-data" / "workspace" / "file.txt"
+        assert expected.exists()
+        assert expected.read_text() == "hello"
+        assert not (base_dir / "threads" / "t1").exists()
+
+    def test_unowned_thread_goes_to_default(self, base_dir: Path, paths: Paths):
+        legacy = base_dir / "threads" / "t2" / "user-data" / "workspace"
+        legacy.mkdir(parents=True)
+
+        from scripts.migrate_user_isolation import migrate_thread_dirs
+        migrate_thread_dirs(paths, thread_owner_map={})
+
+        expected = base_dir / "users" / "default" / "threads" / "t2"
+        assert expected.exists()
+
+    def test_idempotent_skip_already_migrated(self, base_dir: Path, paths: Paths):
+        new_dir = base_dir / "users" / "alice" / "threads" / "t1" / "user-data" / "workspace"
+        new_dir.mkdir(parents=True)
+
+        from scripts.migrate_user_isolation import migrate_thread_dirs
+        migrate_thread_dirs(paths, thread_owner_map={"t1": "alice"})
+        assert new_dir.exists()
+
+    def test_conflict_preserved(self, base_dir: Path, paths: Paths):
+        legacy = base_dir / "threads" / "t1" / "user-data" / "workspace"
+        legacy.mkdir(parents=True)
+        (legacy / "old.txt").write_text("old")
+
+        dest = base_dir / "users" / "alice" / "threads" / "t1" / "user-data" / "workspace"
+        dest.mkdir(parents=True)
+        (dest / "new.txt").write_text("new")
+
+        from scripts.migrate_user_isolation import migrate_thread_dirs
+        migrate_thread_dirs(paths, thread_owner_map={"t1": "alice"})
+
+        assert (dest / "new.txt").read_text() == "new"
+        conflicts = base_dir / "migration-conflicts" / "t1"
+        assert conflicts.exists()
+
+    def test_cleans_up_empty_legacy_dir(self, base_dir: Path, paths: Paths):
+        legacy = base_dir / "threads" / "t1" / "user-data"
+        legacy.mkdir(parents=True)
+
+        from scripts.migrate_user_isolation import migrate_thread_dirs
+        migrate_thread_dirs(paths, thread_owner_map={})
+
+        assert not (base_dir / "threads").exists()
+
+    def test_dry_run_does_not_move(self, base_dir: Path, paths: Paths):
+        legacy = base_dir / "threads" / "t1" / "user-data"
+        legacy.mkdir(parents=True)
+
+        from scripts.migrate_user_isolation import migrate_thread_dirs
+        report = migrate_thread_dirs(paths, thread_owner_map={"t1": "alice"}, dry_run=True)
+
+        assert len(report) == 1
+        assert (base_dir / "threads" / "t1").exists()  # not moved
+        assert not (base_dir / "users" / "alice" / "threads" / "t1").exists()
+
+
+class TestMigrateMemory:
+    def test_moves_global_memory(self, base_dir: Path, paths: Paths):
+        legacy_mem = base_dir / "memory.json"
+        legacy_mem.write_text(json.dumps({"version": "1.0", "facts": []}))
+
+        from scripts.migrate_user_isolation import migrate_memory
+        migrate_memory(paths, user_id="default")
+
+        expected = base_dir / "users" / "default" / "memory.json"
+        assert expected.exists()
+        assert not legacy_mem.exists()
+
+    def test_skips_if_destination_exists(self, base_dir: Path, paths: Paths):
+        legacy_mem = base_dir / "memory.json"
+        legacy_mem.write_text(json.dumps({"version": "old"}))
+
+        dest = base_dir / "users" / "default" / "memory.json"
+        dest.parent.mkdir(parents=True)
+        dest.write_text(json.dumps({"version": "new"}))
+
+        from scripts.migrate_user_isolation import migrate_memory
+        migrate_memory(paths, user_id="default")
+
+        assert json.loads(dest.read_text())["version"] == "new"
+        assert (base_dir / "memory.legacy.json").exists()
+
+    def test_no_legacy_memory_is_noop(self, base_dir: Path, paths: Paths):
+        from scripts.migrate_user_isolation import migrate_memory
+        migrate_memory(paths, user_id="default")  # should not raise