fix: update test fixtures for SQLite storage migration

All store tests were passing file paths instead of Database objects
after the JSON-to-SQLite migration. Updated fixtures to create temp
Database instances, rewrote backup e2e tests for binary .db format,
and fixed config tests for the simplified StorageConfig.

server/tests/storage/test_output_target_store.py

@@ -11,8 +11,8 @@ from wled_controller.storage.key_colors_output_target import (
 
 
 @pytest.fixture
-def store(tmp_path) -> OutputTargetStore:
-    return OutputTargetStore(str(tmp_path / "output_targets.json"))
+def store(tmp_db) -> OutputTargetStore:
+    return OutputTargetStore(tmp_db)
 
 
 # ---------------------------------------------------------------------------
@@ -193,8 +193,10 @@ class TestOutputTargetQueries:
 
 class TestOutputTargetPersistence:
     def test_persist_and_reload(self, tmp_path):
-        path = str(tmp_path / "ot_persist.json")
-        s1 = OutputTargetStore(path)
+        from wled_controller.storage.database import Database
+        db_path = str(tmp_path / "ot_persist.db")
+        db = Database(db_path)
+        s1 = OutputTargetStore(db)
         t = s1.create_target(
             "Persist", "led",
             device_id="dev_1",
@@ -203,8 +205,9 @@ class TestOutputTargetPersistence:
         )
         tid = t.id
 
-        s2 = OutputTargetStore(path)
+        s2 = OutputTargetStore(db)
         loaded = s2.get_target(tid)
         assert loaded.name == "Persist"
         assert isinstance(loaded, WledOutputTarget)
         assert loaded.tags == ["tv"]
+        db.close()