Fix SCXML macrostep ordering and type the execution core

AGENTS.md

@@ -87,7 +87,7 @@ Working:
 
 Known gaps:
 
-- The configured 56-case SCXML suite passes, including all 15 enabled
+- The configured 57-case SCXML suite passes, including all 15 enabled
   `more-parallel` cases, but broader W3C datamodel and executable-content
   conformance is not claimed.
 - Graphviz export and graph/test helper APIs beyond Mermaid are future work.

README.md

@@ -521,7 +521,7 @@ Creating a tag or GitHub Release is not publication authorization.
 | Snapshot queries | `tags`, `meta`, `has_tag`/`hasTag`, and `state_in`/`stateIn` are present |
 | Diagrams | Dependency-free Mermaid export is present |
 | Async | `AsyncInterpreter`, async actors, `from_observable`, and `to_promise` are present |
-| SCXML | Configured 56-case suite passes, including all 15 enabled `more-parallel` cases; broader W3C coverage remains open |
+| SCXML | Configured 57-case suite passes, including all 15 enabled `more-parallel` cases; broader W3C coverage remains open |
 | Persistence | Snapshot serialization and restore helpers are present |
 | Documentation | Concept guides cover machines, runtimes, actors, persistence, and SCXML import |
 | Examples | `docs/examples/` is the canonical, subprocess-tested example collection |

pyproject.toml

@@ -88,11 +88,18 @@ warn_unused_ignores = true
 no_implicit_optional = true
 no_implicit_reexport = true
 
-# algorithm.py implements W3C SCXML; internal control-flow helpers still use
-# loose signatures while the parsed config boundary is now typed separately.
+# The SCXML execution core is correctness-critical and must remain fully typed.
 [[tool.mypy.overrides]]
 module = "xstate.algorithm"
-disallow_untyped_defs = false
+disallow_any_generics = true
+disallow_subclassing_any = true
+disallow_untyped_calls = true
+disallow_untyped_defs = true
+disallow_incomplete_defs = true
+check_untyped_defs = true
+disallow_untyped_decorators = true
+strict_equality = true
+extra_checks = true
 
 
 [tool.pytest.ini_options]