fix: 🐛 ScopeFacade can be threadsafe

[remimd]

No description provided.

[Copilot]

Pull Request Overview

This PR makes ScopeFacade thread-safe by introducing a shared lock for binding and slot updates.

• Pass a lock into _UserScope and use it to guard slot_map operations
• Inline the binder context call and preserve locking for unbinding

Comments suppressed due to low confidence (2)

injection/_core/scope.py:327

• [nitpick] The attribute name lock is generic and may collide with other variables; consider renaming to _scope_lock or similar to clarify its purpose and mark it as internal.

lock: ContextManager[Any]

injection/_core/scope.py:335

• There are no tests covering concurrent calls to slot_map. Adding a test that runs slot_map from multiple threads would help ensure the new locking logic behaves correctly under contention.

with self.lock: