test: bring coverage to 85%, set threshold to 85, reset version to 3.0.11

- Add tests for config, convo_miner, spellcheck, knowledge_graph
- Fix Windows PermissionError in test cleanup (chromadb file locks)
- Add UTF-8 encoding to split_mega_files, entity_registry, hooks_cli
- Fix mcp_server parse_known_args logging for unknown args
- Set coverage threshold to 85 in pyproject.toml and CI
- Reset all version files to 3.0.11

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tests/test_miner.py

@@ -47,7 +47,7 @@ def test_project_mining():
         col = client.get_collection("mempalace_drawers")
         assert col.count() > 0
     finally:
-        shutil.rmtree(tmpdir)
+        shutil.rmtree(tmpdir, ignore_errors=True)
 
 
 def test_scan_project_respects_gitignore():