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_spellcheck_extra.py

@@ -0,0 +1,72 @@
+"""Extra spellcheck tests covering _load_known_names and speller edge cases."""
+
+from unittest.mock import patch, MagicMock
+
+from mempalace.spellcheck import (
+    _load_known_names,
+    spellcheck_user_text,
+)
+
+
+class TestLoadKnownNames:
+    def test_returns_names_from_registry(self):
+        mock_reg = MagicMock()
+        mock_reg._data = {
+            "entities": {
+                "e1": {"canonical": "Alice", "aliases": ["ali"]},
+                "e2": {"canonical": "Bob", "aliases": []},
+            }
+        }
+        with patch("mempalace.entity_registry.EntityRegistry") as MockER:
+            MockER.load.return_value = mock_reg
+            names = _load_known_names()
+            assert "alice" in names
+            assert "ali" in names
+            assert "bob" in names
+
+    def test_returns_empty_on_exception(self):
+        with patch(
+            "mempalace.entity_registry.EntityRegistry.load",
+            side_effect=Exception("no registry"),
+        ):
+            names = _load_known_names()
+            assert names == set()
+
+
+class TestSpellerEdgeCases:
+    def test_capitalized_word_skipped(self):
+        """Capitalized words (likely proper nouns) are not corrected."""
+
+        def fake_speller(word):
+            return "WRONG"
+
+        with patch("mempalace.spellcheck._get_speller", return_value=fake_speller):
+            with patch("mempalace.spellcheck._get_system_words", return_value=set()):
+                with patch("mempalace.spellcheck._load_known_names", return_value=set()):
+                    result = spellcheck_user_text("Alice went home")
+                    assert "Alice" in result
+                    assert "WRONG" not in result
+
+    def test_system_word_not_corrected(self):
+        """Words in system dict should not be corrected."""
+
+        def fake_speller(word):
+            return "WRONG"
+
+        with patch("mempalace.spellcheck._get_speller", return_value=fake_speller):
+            with patch("mempalace.spellcheck._get_system_words", return_value={"coherently"}):
+                with patch("mempalace.spellcheck._load_known_names", return_value=set()):
+                    result = spellcheck_user_text("coherently")
+                    assert "coherently" in result
+
+    def test_high_edit_distance_rejected(self):
+        """Corrections with too many edits are rejected."""
+
+        def fake_speller(word):
+            return "completely_different_word"
+
+        with patch("mempalace.spellcheck._get_speller", return_value=fake_speller):
+            with patch("mempalace.spellcheck._get_system_words", return_value=set()):
+                with patch("mempalace.spellcheck._load_known_names", return_value=set()):
+                    result = spellcheck_user_text("hello")
+                    assert "hello" in result