hotfix: missing hash property on Message

Author: monoxgas

docs/api/message.mdx

@@ -733,6 +733,14 @@ content_parts: list[Content] = Field([], repr=False)
 
 Interior str content or structured content parts.
 
+### hash
+
+```python
+hash: int
+```
+
+Returns a weak hash of the functional message content, ignoring UUID, metadata, and supplementary fields.
+
 ### metadata
 
 ```python

rigging/message.py

@@ -502,6 +502,13 @@ def rename_content(self, handler: SerializerFunctionWrapHandler) -> t.Any:
             serialized["content"] = serialized.pop("content_parts")
         return serialized
 
+    @property
+    def hash(self) -> int:
+        """
+        Returns a weak hash of the functional message content, ignoring UUID, metadata, and supplementary fields.
+        """
+        return hash(str(self.to_openai(compatibility_flags=set())))
+
     @property
     @te.deprecated(".all_content is deprecated, use .content_parts instead", category=None)
     def all_content(self) -> str | list[Content]: