Add types.sx gradual type system spec module with 44 tests

Implements subtype checking, type inference, type narrowing, and
component call-site checking. All type logic is in types.sx (spec),
bootstrapped to every host. Adds test-types.sx with full coverage.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

shared/sx/tests/run.py

@@ -262,6 +262,7 @@ SPECS = {
     "engine":        {"file": "test-engine.sx",        "needs": []},
     "orchestration": {"file": "test-orchestration.sx", "needs": []},
     "signals":       {"file": "test-signals.sx",       "needs": ["make-signal"]},
+    "types":         {"file": "test-types.sx",         "needs": []},
 }
 
 REF_DIR = os.path.join(_HERE, "..", "ref")
@@ -722,6 +723,78 @@ def _load_signals(env):
     env["batch"] = _batch
 
 
+def _load_types(env):
+    """Load types.sx spec — gradual type system."""
+    from shared.sx.types import Component
+
+    def _component_param_types(c):
+        return getattr(c, 'param_types', None)
+
+    def _component_set_param_types(c, d):
+        c.param_types = d
+
+    env["component-param-types"] = _component_param_types
+    env["component-set-param-types!"] = _component_set_param_types
+
+    # test-prim-types: a minimal type registry for testing
+    def _test_prim_types():
+        return {
+            "+": "number", "-": "number", "*": "number", "/": "number",
+            "mod": "number", "abs": "number", "floor": "number",
+            "ceil": "number", "round": "number", "min": "number",
+            "max": "number", "parse-int": "number", "parse-float": "number",
+            "=": "boolean", "!=": "boolean", "<": "boolean", ">": "boolean",
+            "<=": "boolean", ">=": "boolean",
+            "str": "string", "string-length": "number",
+            "substring": "string", "upcase": "string", "downcase": "string",
+            "trim": "string", "split": "list", "join": "string",
+            "string-contains?": "boolean", "starts-with?": "boolean",
+            "ends-with?": "boolean", "replace": "string",
+            "not": "boolean", "nil?": "boolean", "number?": "boolean",
+            "string?": "boolean", "list?": "boolean", "dict?": "boolean",
+            "boolean?": "boolean", "symbol?": "boolean", "empty?": "boolean",
+            "list": "list", "first": "any", "rest": "list", "nth": "any",
+            "last": "any", "cons": "list", "append": "list",
+            "reverse": "list", "len": "number", "contains?": "boolean",
+            "flatten": "list", "concat": "list", "slice": "list",
+            "range": "list", "sort": "list", "sort-by": "list",
+            "map": "list", "filter": "list", "reduce": "any",
+            "some": "boolean", "every?": "boolean",
+            "dict": "dict", "assoc": "dict", "dissoc": "dict",
+            "get": "any", "keys": "list", "vals": "list",
+            "has-key?": "boolean", "merge": "dict",
+        }
+
+    env["test-prim-types"] = _test_prim_types
+    env["test-env"] = lambda: env
+
+    # Try bootstrapped types first, fall back to eval
+    try:
+        from shared.sx.ref.sx_ref import (
+            subtype_p, type_union, narrow_type,
+            infer_type, check_component_call, check_component,
+            check_all, build_type_registry, type_any_p,
+            type_never_p, type_nullable_p, nullable_base,
+            narrow_exclude_nil, narrow_exclude,
+        )
+        env["subtype?"] = subtype_p
+        env["type-union"] = type_union
+        env["narrow-type"] = narrow_type
+        env["infer-type"] = infer_type
+        env["check-component-call"] = check_component_call
+        env["check-component"] = check_component
+        env["check-all"] = check_all
+        env["build-type-registry"] = build_type_registry
+        env["type-any?"] = type_any_p
+        env["type-never?"] = type_never_p
+        env["type-nullable?"] = type_nullable_p
+        env["nullable-base"] = nullable_base
+        env["narrow-exclude-nil"] = narrow_exclude_nil
+        env["narrow-exclude"] = narrow_exclude
+    except ImportError:
+        eval_file("types.sx", env)
+
+
 def main():
     global passed, failed, test_num
 
@@ -769,6 +842,8 @@ def main():
                 _load_orchestration(env)
             if spec_name == "signals":
                 _load_signals(env)
+            if spec_name == "types":
+                _load_types(env)
 
             print(f"# --- {spec_name} ---")
             eval_file(spec["file"], env)