feat: Add on_package_loaded event

docs/extensions.md

@@ -190,7 +190,6 @@ contains a single class, which itself contains a single method:
 - then it will go back up and finish walking since there are
   no more nodes to walk through
 
-
 Every time the agent enters a node,
 creates an object instance,
 or finish handling members of an object,
@@ -256,13 +255,33 @@ and how to hook onto them in your extensions.
 
 ### Events and hooks
 
-There are 3 generic **events**:
+There are two kinds of events in Griffe:
+**load events** and **analysis events**.
+Load events are scoped to the Griffe loader.
+Analysis events are scoped to the visitor and inspector agents
+(triggered during static and dynamic analysis).
+
+#### Load events
+
+There is only one **load event**:
+
+- [`on_package_loaded`][griffe.extensions.base.Extension.on_package_loaded] 
+
+This event is triggered when the loader has finished loading a package entirely,
+i.e. when all its submodules were scanned and loaded.
+This event can be hooked by extensions which require the whole package to be loaded,
+to be able to navigate the object tree without raising lookup errors
+or alias resolution errors.
+
+#### Analysis events
+
+There are 3 generic **analysis events**:
 
 - [`on_node`][griffe.extensions.base.Extension.on_node]
 - [`on_instance`][griffe.extensions.base.Extension.on_instance]
 - [`on_members`][griffe.extensions.base.Extension.on_members]
 
-There are also specific **events** for each object kind:
+There are also specific **analysis events** for each object kind:
 
 - [`on_module_node`][griffe.extensions.base.Extension.on_module_node]
 - [`on_module_instance`][griffe.extensions.base.Extension.on_module_instance]

src/griffe/extensions/base.py

@@ -226,6 +226,13 @@ def on_attribute_instance(self, *, node: ast.AST | ObjectNode, attr: Attribute)
             attr: The attribute instance.
         """
 
+    def on_package_loaded(self, *, pkg: Module) -> None:
+        """Run when a package has been completely loaded.
+
+        Parameters:
+            pkg: The package (Module) instance.
+        """
+
 
 ExtensionType = Union[VisitorExtension, InspectorExtension, Extension]
 
@@ -326,16 +333,15 @@ def after_inspection(self) -> list[InspectorExtension]:
         """The inspectors that run after the inspection."""
         return self._inspectors[When.after_all]
 
-    def call(self, event: str, *, node: ast.AST | ObjectNode, **kwargs: Any) -> None:
+    def call(self, event: str, **kwargs: Any) -> None:
         """Call the extension hook for the given event.
 
         Parameters:
             event: The trigerred event.
-            node: The AST or Object node.
-            **kwargs: Additional arguments like a Griffe object.
+            **kwargs: Arguments passed to the hook.
         """
         for extension in self._extensions:
-            getattr(extension, event)(node=node, **kwargs)
+            getattr(extension, event)(**kwargs)
 
 
 builtin_extensions: set[str] = {