fix: improve Steward delegation instructions for Librarian

- Update Librarian capability description to highlight CREATE/UPDATE/SEARCH
- Add specific Steward guidelines for wiki creation, updates, and research
- Add dynamic time injection to user prompts for temporal awareness
- Expand domains to include 'create', 'write', 'update'
- Update test to match new capability description

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

tests/agents/librarian/test_capability.py

@@ -113,9 +113,12 @@ class TestLibrarianRegistration:
 class TestCapabilityDescription:
     """Tests for capability description."""
 
-    def test_description_mentions_library_desk(self):
-        """Test description mentions library-desk API."""
-        assert "library-desk" in LIBRARIAN_CAPABILITY.description.lower()
+    def test_description_mentions_wiki_capabilities(self):
+        """Test description mentions wiki read/write capabilities."""
+        desc = LIBRARIAN_CAPABILITY.description.lower()
+        assert "create" in desc
+        assert "update" in desc
+        assert "search" in desc
 
     def test_description_mentions_search(self):
         """Test description mentions search capability."""