fix: force-close StaticPool DBAPI connection to release SQLite locks

StaticPool._close_connection() is a no-op, so engine.dispose() alone
never closes the underlying sqlite3 connection. On Windows, this leaves
mandatory file locks in place, causing PermissionError when tests try
to delete the database file.

Use Connection.invalidate() which bypasses the pool's _close_connection
and calls dialect.do_close() directly to actually close the DBAPI
connection. Also add gc.collect() in initialize_storage to ensure any
lingering references are cleaned up before file removal.

Author: MDUYN

investing_algorithm_framework/app/app.py

@@ -378,8 +378,19 @@ def initialize_storage(self, remove_database_if_exists: bool = False):
                 bind = Session.kw.get("bind")
 
                 if bind is not None:
+
+                    try:
+                        conn = bind.connect()
+                        conn.invalidate()
+                        conn.close()
+                    except Exception:
+                        pass
+
                     bind.dispose()
 
+                import gc
+                gc.collect()
+
                 os.remove(database_path)
 
         # Create the sqlalchemy database uri

investing_algorithm_framework/infrastructure/database/sql_alchemy.py

@@ -93,6 +93,19 @@ def teardown_sqlalchemy():
     bind = Session.kw.get("bind")
 
     if bind is not None:
+
+        # StaticPool._close_connection() is a no-op, so
+        # engine.dispose() alone won't close the underlying DBAPI
+        # connection. Use invalidate() which bypasses the pool's
+        # _close_connection and calls dialect.do_close() directly,
+        # ensuring the sqlite3 file lock is released on Windows.
+        try:
+            conn = bind.connect()
+            conn.invalidate()
+            conn.close()
+        except Exception:
+            pass
+
         bind.dispose()
 
     Session.configure(bind=None)