make sure adapters can access the context of their parent chain

#456

src/refiners/fluxion/layers/chain.py

@@ -609,6 +609,7 @@ def replace(
             new_module._set_parent(self)
         if isinstance(old_module, ContextModule):
             old_module._set_parent(old_module_parent)
+        self._register_provider()
 
     def structural_copy(self: TChain) -> TChain:
         """Copy the structure of the Chain tree.

tests/adapters/test_adapter_context.py

@@ -0,0 +1,25 @@
+import refiners.fluxion.layers as fl
+from refiners.fluxion.adapters.adapter import Adapter
+from refiners.fluxion.context import Contexts
+
+
+class ContextAdapter(fl.Chain, Adapter[fl.Chain]):
+    def __init__(self, target: fl.Chain):
+        with self.setup_adapter(target):
+            super().__init__(
+                fl.Lambda(lambda: 42),
+                fl.SetContext("foo", "bar"),
+            )
+
+
+class ContextChain(fl.Chain):
+    def init_context(self) -> Contexts:
+        return {"foo": {"bar": None}}
+
+
+def test_adapter_can_access_parent_context():
+    chain = ContextChain(fl.Chain(), fl.UseContext("foo", "bar"))
+    adaptee = chain.layer("Chain", fl.Chain)
+    ContextAdapter(adaptee).inject(chain)
+
+    assert chain() == 42