Map RNA float array properties to mathutils types using subtype

RNA properties with subtypes like TRANSLATION, XYZ, EULER, QUATERNION,
COLOR, MATRIX are now mapped to the corresponding mathutils types
(Vector, Euler, Quaternion, Color, Matrix) instead of list[float].

Also:
- Add gpu.types override for 5.1 (uniform_float accepts mathutils types)
- Fix README snippet to use assert for active_object None check

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

introspect.py

@@ -2138,6 +2138,21 @@ def rna_property_to_type(prop: object) -> str:
         if array_length == 0 and is_array:
             # Dynamic-length array — at runtime this is a bpy_prop_array
             return f"bpy_prop_array[{base}]"
+        # Fixed-length float arrays with vector/matrix subtypes are mathutils types
+        subtype: str = getattr(prop, "subtype", "NONE")
+        if prop_type == "float" and subtype in (
+            "TRANSLATION", "DIRECTION", "VELOCITY", "ACCELERATION",
+            "XYZ", "XYZ_LENGTH",
+        ):
+            return "mathutils.Vector"
+        if prop_type == "float" and subtype == "EULER":
+            return "mathutils.Euler"
+        if prop_type == "float" and subtype == "QUATERNION":
+            return "mathutils.Quaternion"
+        if prop_type == "float" and subtype in ("COLOR", "COLOR_GAMMA") and array_length == 3:
+            return "mathutils.Color"
+        if prop_type == "float" and subtype == "MATRIX":
+            return "mathutils.Matrix"
         return f"list[{base}]"
 
     return RNA_TYPE_MAP.get(prop_type, prop_type)