Close local release-quality gaps and reconcile workplan status

Assistant: codex
Assistant-Model: gpt-6-astra
Assistant-Session: 01a0e332-3365-77c0-8491-084e9ea33ac1

llm_connect/quality.py

@@ -8,13 +8,14 @@ from __future__ import annotations
 
 import json
 import os
+import sys
 import threading
+from collections.abc import Iterator
 from contextlib import contextmanager
 from dataclasses import dataclass, field
 from datetime import datetime, timedelta, timezone
 from pathlib import Path
-from typing import Any, Iterator, TextIO
-
+from typing import Any, Literal, TextIO
 
 _PATH_LOCKS: dict[Path, threading.Lock] = {}
 _PATH_LOCKS_GUARD = threading.Lock()
@@ -62,7 +63,7 @@ def _path_lock(path: Path) -> threading.Lock:
 
 
 def _lock_file(handle: TextIO) -> None:
-    if os.name == "nt":
+    if sys.platform == "win32":
         import msvcrt
 
         msvcrt.locking(handle.fileno(), msvcrt.LK_LOCK, 1)
@@ -73,7 +74,7 @@ def _lock_file(handle: TextIO) -> None:
 
 
 def _unlock_file(handle: TextIO) -> None:
-    if os.name == "nt":
+    if sys.platform == "win32":
         import msvcrt
 
         msvcrt.locking(handle.fileno(), msvcrt.LK_UNLCK, 1)
@@ -84,7 +85,7 @@ def _unlock_file(handle: TextIO) -> None:
 
 
 @contextmanager
-def _locked_file(path: Path, mode: str) -> Iterator[TextIO]:
+def _locked_file(path: Path, mode: Literal["a", "a+", "r"]) -> Iterator[TextIO]:
     path.parent.mkdir(parents=True, exist_ok=True)
     local_lock = _path_lock(path)
     with local_lock:
@@ -157,7 +158,7 @@ class QualityObservation:
         }
 
     @classmethod
-    def from_dict(cls, data: dict[str, Any]) -> "QualityObservation":
+    def from_dict(cls, data: dict[str, Any]) -> QualityObservation:
         """Create an observation from a JSON-decoded dictionary."""
         return cls(
             task_type=data["task_type"],