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>

mempalace/entity_registry.py

@@ -309,7 +309,7 @@ class EntityRegistry:
 
     def save(self):
         self._path.parent.mkdir(parents=True, exist_ok=True)
-        self._path.write_text(json.dumps(self._data, indent=2))
+        self._path.write_text(json.dumps(self._data, indent=2), encoding="utf-8")
 
     @staticmethod
     def _empty() -> dict:

mempalace/hooks_cli.py

@@ -150,7 +150,7 @@ def hook_stop(data: dict, harness: str):
     if since_last >= SAVE_INTERVAL and exchange_count > 0:
         # Update last save point
         try:
-            last_save_file.write_text(str(exchange_count))
+            last_save_file.write_text(str(exchange_count), encoding="utf-8")
         except OSError:
             pass
 

mempalace/mcp_server.py

@@ -44,7 +44,9 @@ def _parse_args():
         metavar="PATH",
         help="Path to the palace directory (overrides config file and env var)",
     )
-    args, _ = parser.parse_known_args()
+    args, unknown = parser.parse_known_args()
+    if unknown:
+        logger.debug("Ignoring unknown args: %s", unknown)
     return args
 
 

mempalace/split_mega_files.py

@@ -219,7 +219,7 @@ def split_file(filepath, output_dir, dry_run=False):
         if dry_run:
             print(f"  [{i + 1}/{len(boundaries) - 1}] {name}  ({len(chunk)} lines)")
         else:
-            out_path.write_text("".join(chunk))
+            out_path.write_text("".join(chunk), encoding="utf-8")
             print(f"  ✓ {name}  ({len(chunk)} lines)")
 
         written.append(out_path)

mempalace/version.py

@@ -1,3 +1,3 @@
 """Single source of truth for the MemPalace package version."""
 
-__version__ = "3.0.15"
+__version__ = "3.0.11"