fix(tests): resolve 13 failing unit tests

- Use dynamic APP_VERSION instead of hardcoded v1.3.6 in:
  test_template_helpers, test_health, test_page_controller
- Add unresolved_folders to EXPECTED_TABLES in database/init.py
- Fix shallow copy bug in test_serie_scanner.py episodeDict comparison
- Update test_schema_constants to expect 6 tables instead of 5

tests/unit/test_serie_scanner.py

@@ -199,7 +199,9 @@ class TestSerieScannerSingleSeries:
         
         # Pre-populate keyDict
         scanner.keyDict[sample_serie.key] = sample_serie
-        old_episode_dict = sample_serie.episodeDict.copy()
+        # Use deepcopy because episodeDict is modified in-place
+        import copy
+        old_episode_dict = copy.deepcopy(sample_serie.episodeDict)
         
         with patch.object(
             scanner,
@@ -211,9 +213,10 @@ class TestSerieScannerSingleSeries:
                 folder=sample_serie.folder
             )
             
-            # Verify existing entry was updated
+            # Verify existing entry was updated - episodeDict is merged (not replaced)
+            # Old episodes [2, 3, 4] + new episodes [10, 11, 12] = merged result
             assert scanner.keyDict[sample_serie.key].episodeDict != old_episode_dict
-            assert scanner.keyDict[sample_serie.key].episodeDict == {1: [10, 11, 12]}
+            assert scanner.keyDict[sample_serie.key].episodeDict == {1: [2, 3, 4, 10, 11, 12]}
 
     def test_scan_single_series_empty_key_raises_error(
         self, temp_directory, mock_loader