core/tools: drop process workspace/todo globals; require bound state

tests/test_tools/conftest.py

@@ -4,6 +4,7 @@ from typing import TYPE_CHECKING
 
 import pytest
 
+from plyngent.tools.context import InstanceState, bind_instance
 from plyngent.tools.workspace import (
     clear_workspace_allowlist,
     clear_workspace_root,
@@ -17,9 +18,11 @@ if TYPE_CHECKING:
 
 @pytest.fixture
 def workspace(tmp_path: Path) -> Iterator[Path]:
-    clear_workspace_root()
-    clear_workspace_allowlist()
-    root = set_workspace_root(tmp_path)
-    yield root
-    clear_workspace_allowlist()
-    clear_workspace_root()
+    """Bind an InstanceState workspace for tool tests (no process globals)."""
+    instance = InstanceState(workspace_root=tmp_path.resolve())
+    with bind_instance(instance):
+        clear_workspace_allowlist()
+        root = set_workspace_root(tmp_path)
+        yield root
+        clear_workspace_allowlist()
+        clear_workspace_root()