fix(conductor): Apply review suggestions for track 'history_segregation'

project_manager.py

@@ -122,11 +122,16 @@ def default_project(name: str = "unnamed") -> dict:
 # ── load / save ──────────────────────────────────────────────────────────────
 
 def get_history_path(project_path: str | Path) -> Path:
+    """Return the Path to the sibling history TOML file for a given project."""
     p = Path(project_path)
     return p.parent / f"{p.stem}_history.toml"
 
 
-def load_project(path) -> dict:
+def load_project(path: str | Path) -> dict:
+    """
+    Load a project TOML file.
+    Automatically migrates legacy 'discussion' keys to a sibling history file.
+    """
     with open(path, "rb") as f:
         proj = tomllib.load(f)
     
@@ -150,6 +155,7 @@ def load_project(path) -> dict:
 
 
 def load_history(project_path: str | Path) -> dict:
+    """Load the segregated discussion history from its dedicated TOML file."""
     hist_path = get_history_path(project_path)
     if hist_path.exists():
         with open(hist_path, "rb") as f:
@@ -157,7 +163,11 @@ def load_history(project_path: str | Path) -> dict:
     return {}
 
 
-def save_project(proj: dict, path, disc_data: dict | None = None):
+def save_project(proj: dict, path: str | Path, disc_data: dict | None = None):
+    """
+    Save the project TOML.
+    If 'discussion' is present in proj, it is moved to the sibling history file.
+    """
     # Ensure 'discussion' is NOT in the main project dict
     if "discussion" in proj:
         # If disc_data wasn't provided, use the one from proj