fix(type): Resolve all pyrefly type errors

This commit resolves all type errors reported by pyrefly.

The following changes were made:
- tests/test_real_data.py: Adjusted assertions to correctly access model_extra attributes and check for None values for optional fields.
- tests/test_registry.py: Corrected type hints for MINIMAL_PRELOADS and CustomObject.type to align with expected types. Imported Optional.
- src/apmodel/_core/_initial/_rebuild.py: Updated type hint for models_to_rebuild to List[Type[ActivityPubModel]] and removed Nodeinfo related classes as they do not inherit ActivityPubModel. Also simplified the rebuild loop.
- src/apmodel/_core/key.py: Added ValueError for unsupported key types to ensure 'wrapped' is always initialized.
- src/apmodel/context.py: Removed __iter__ method from LDContext as it was inconsistent with BaseModel's __iter__.
- src/apmodel/core/collection.py: Used typing.cast to explicitly cast return values of load functions in field validators. Imported cast.
- src/apmodel/extra/litepub/emoji_react.py: Changed EmojiReact.content type to Optional[str] to match parent class Like. Imported Optional.
- src/apmodel/_core/_initial/_registry_bootstrap.py: Added explicit type hint for TYPE_MAPPING to ensure compatibility with ModelRegistry.
- src/apmodel/vocab/activity/question.py: Used typing.cast to explicitly cast return values of load functions in field validators. Imported cast.
- src/apmodel/vocab/tombstone.py: Used typing.cast to explicitly cast return values of load functions in field validators. Imported cast.

Author: AmaseCocoa

src/apmodel/_core/_initial/_registry_bootstrap.py

@@ -1,4 +1,8 @@
-TYPE_MAPPING = {
+from typing import Dict, Type, Union
+
+from apmodel.types import ActivityPubModel
+
+TYPE_MAPPING: Dict[str, Union[str, Type[ActivityPubModel]]] = {
     "https://www.w3.org/ns/activitystreams#Activity": "apmodel.core.activity.Activity",
     "https://www.w3.org/ns/activitystreams#IntransitiveActivity": "apmodel.core.activity.IntransitiveActivity",
     "https://www.w3.org/ns/activitystreams#Collection": "apmodel.core.collection.Collection",

src/apmodel/core/collection.py

@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-from typing import Any, List, Optional
+from typing import Any, List, Optional, cast
 
 from pydantic import Field, field_validator
 from typing_extensions import Dict
@@ -28,7 +28,7 @@ def validate_ordered_items(
 
         if not v:
             return None
-        return load(v, "raw")
+        return cast(Optional[List[Object | Link | Dict[str, Any]]], load(v, "raw"))
 
     @field_validator("items")
     @classmethod
@@ -39,7 +39,7 @@ def validate_items(
 
         if not v:
             return None
-        return load(v, "raw")
+        return cast(Optional[List[Object | Link | Dict[str, Any]]], load(v, "raw"))
 
 
 class CollectionPage(Collection):

src/apmodel/extra/litepub/emoji_react.py

@@ -1,5 +1,7 @@
+from typing import Optional
+
 from ...vocab.activity.like import Like
 
 
 class EmojiReact(Like):
-    content: str
+    content: Optional[str]

src/apmodel/vocab/activity/question.py

@@ -1,5 +1,5 @@
 import datetime
-from typing import Any, Optional
+from typing import Any, Optional, cast
 
 from pydantic import Field, field_serializer, field_validator
 from typing_extensions import Dict
@@ -26,7 +26,7 @@ def validate_one_of(
             return None
         from ...loader import load
 
-        return load(v, "raw")
+        return cast(Optional[str | Object | Link | Dict[str, Any]], load(v, "raw"))
 
     @field_validator("any_of", mode="before")
     @classmethod
@@ -37,7 +37,7 @@ def validate_any_of(
             return None
         from ...loader import load
 
-        return load(v, "raw")
+        return cast(Optional[str | Object | Link | Dict[str, Any]], load(v, "raw"))
 
     @field_validator("closed", mode="before")
     @classmethod
@@ -48,7 +48,7 @@ def validate_closed(
             return None
         from ...loader import load
 
-        return load(v, "raw")
+        return cast(Optional[str | Object | Link | Dict[str, Any]], load(v, "raw"))
 
     @field_serializer("closed", when_used="always")
     def serialize_closed(self, value: Any, _) -> str | bool | Any:

src/apmodel/vocab/tombstone.py

@@ -1,5 +1,5 @@
 import datetime
-from typing import Any, Optional
+from typing import Any, Optional, cast
 
 from pydantic import Field, field_serializer, field_validator
 from typing_extensions import Dict
@@ -23,7 +23,7 @@ def validate_former_type(
 
         if not v:
             return None
-        return load(v, "raw")
+        return cast(Optional[str | Object | Dict[str, Any]], load(v, "raw"))
 
     @field_validator("deleted", mode="before")
     @classmethod