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_convo_miner_unit.py

@@ -0,0 +1,102 @@
+"""Unit tests for convo_miner pure functions (no chromadb needed)."""
+
+from mempalace.convo_miner import (
+    chunk_exchanges,
+    detect_convo_room,
+    scan_convos,
+)
+
+
+class TestChunkExchanges:
+    def test_exchange_chunking(self):
+        content = (
+            "> What is memory?\n"
+            "Memory is persistence of information over time.\n\n"
+            "> Why does it matter?\n"
+            "It enables continuity across sessions and conversations.\n\n"
+            "> How do we build it?\n"
+            "With structured storage and retrieval mechanisms.\n"
+        )
+        chunks = chunk_exchanges(content)
+        assert len(chunks) >= 2
+        assert all("content" in c and "chunk_index" in c for c in chunks)
+
+    def test_paragraph_fallback(self):
+        """Content without '>' lines falls back to paragraph chunking."""
+        content = (
+            "This is a long paragraph about memory systems. " * 10 + "\n\n"
+            "This is another paragraph about storage. " * 10 + "\n\n"
+            "And a third paragraph about retrieval. " * 10
+        )
+        chunks = chunk_exchanges(content)
+        assert len(chunks) >= 2
+
+    def test_paragraph_line_group_fallback(self):
+        """Long content with no paragraph breaks chunks by line groups."""
+        lines = [f"Line {i}: some content that is meaningful" for i in range(60)]
+        content = "\n".join(lines)
+        chunks = chunk_exchanges(content)
+        assert len(chunks) >= 1
+
+    def test_empty_content(self):
+        chunks = chunk_exchanges("")
+        assert chunks == []
+
+    def test_short_content_skipped(self):
+        chunks = chunk_exchanges("> hi\nbye")
+        # Too short to produce chunks (below MIN_CHUNK_SIZE)
+        assert isinstance(chunks, list)
+
+
+class TestDetectConvoRoom:
+    def test_technical_room(self):
+        content = "Let me debug this python function and fix the code error in the api"
+        assert detect_convo_room(content) == "technical"
+
+    def test_planning_room(self):
+        content = "We need to plan the roadmap for the next sprint and set milestone deadlines"
+        assert detect_convo_room(content) == "planning"
+
+    def test_architecture_room(self):
+        content = "The architecture uses a service layer with component interface and module design"
+        assert detect_convo_room(content) == "architecture"
+
+    def test_decisions_room(self):
+        content = "We decided to switch and migrated to the new framework after we chose it"
+        assert detect_convo_room(content) == "decisions"
+
+    def test_general_fallback(self):
+        content = "Hello, how are you doing today? The weather is nice."
+        assert detect_convo_room(content) == "general"
+
+
+class TestScanConvos:
+    def test_scan_finds_txt_and_md(self, tmp_path):
+        (tmp_path / "chat.txt").write_text("hello", encoding="utf-8")
+        (tmp_path / "notes.md").write_text("world", encoding="utf-8")
+        (tmp_path / "image.png").write_bytes(b"fake")
+        files = scan_convos(str(tmp_path))
+        extensions = {f.suffix for f in files}
+        assert ".txt" in extensions
+        assert ".md" in extensions
+        assert ".png" not in extensions
+
+    def test_scan_skips_git_dir(self, tmp_path):
+        git_dir = tmp_path / ".git"
+        git_dir.mkdir()
+        (git_dir / "config.txt").write_text("git stuff", encoding="utf-8")
+        (tmp_path / "chat.txt").write_text("hello", encoding="utf-8")
+        files = scan_convos(str(tmp_path))
+        assert len(files) == 1
+
+    def test_scan_skips_meta_json(self, tmp_path):
+        (tmp_path / "chat.meta.json").write_text("{}", encoding="utf-8")
+        (tmp_path / "chat.json").write_text("{}", encoding="utf-8")
+        files = scan_convos(str(tmp_path))
+        names = [f.name for f in files]
+        assert "chat.json" in names
+        assert "chat.meta.json" not in names
+
+    def test_scan_empty_dir(self, tmp_path):
+        files = scan_convos(str(tmp_path))
+        assert files == []