IAM tech spec: Auth and access management current state and proposed

changes.

Workspace support:
- Support for separate workspaces
- Addition of workspace CLI support for test purposes
- Massive test update
- Remove many 'user' references in services - workspace now provides
  the same separation
- Update API

tests/unit/test_chunking/test_token_chunker.py

@@ -185,7 +185,6 @@ class TestTokenChunkerSimple(IsolatedAsyncioTestCase):
         mock_text_doc = MagicMock()
         mock_text_doc.metadata = Metadata(
             id="test-doc-456",
-            user="test-user",
             collection="test-collection"
         )
         mock_text_doc.text = b"This is test document content for token chunking"