Stabilize core correctness and sync project plan state

src/atocore/ingestion/chunker.py

@@ -3,7 +3,7 @@
 import re
 from dataclasses import dataclass, field
 
-from atocore.config import settings
+import atocore.config as _config
 
 
 @dataclass
@@ -29,9 +29,9 @@ def chunk_markdown(
     3. If still > max_size, split on paragraph breaks
     4. If still > max_size, hard split with overlap
     """
-    max_size = max_size or settings.chunk_max_size
-    overlap = overlap or settings.chunk_overlap
-    min_size = min_size or settings.chunk_min_size
+    max_size = max_size or _config.settings.chunk_max_size
+    overlap = overlap or _config.settings.chunk_overlap
+    min_size = min_size or _config.settings.chunk_min_size
     base_metadata = base_metadata or {}
 
     sections = _split_by_heading(body, level=2)