Add function-scoped Logic visualization

src/docforge/models.py

@@ -204,6 +204,13 @@ class IncrementalStateProject(ProjectService, Protocol):
     def incremental_state(self) -> ProjectState | None: ...
 
 
+@runtime_checkable
+class LogicProject(ProjectService, Protocol):
+    """Optional project boundary exposing logic from its most recent validated load."""
+
+    def logic_projections(self) -> tuple[LogicProjection, ...]: ...
+
+
 @dataclass(frozen=True)
 class ContextEntry:
     node_id: str